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Cocrystal Controlled Solid-State Synthesis: A Green Chemistry Experiment for Undergraduate Organic Chemistry
ERIC Educational Resources Information Center
Cheney, Miranda L.; Zaworotko, Michael J.; Beaton, Steve; Singer, Robert D.
Green chemistry has become an important area of concern for all chemists from practitioners in the pharmaceutical industry to professors and the students they teach and is now being incorporated into lectures of general and organic chemistry courses. However, there are relatively few green chemistry experiments that are easily incorporated into…
An Organic Chemistry Experiment for Forensic Science Majors.
ERIC Educational Resources Information Center
Rothchild, Robert
The laboratory experiment described here is intended to be of use to the forensic science major enrolled in a course in organic chemistry. The experiment is the use of thin-layer chromotography for qualitative analysis, specifically for the identification of drugs. (Author/SA)
Synthesis of Bisphenol Z: An Organic Chemistry Experiment
ERIC Educational Resources Information Center
Gregor, Richard W.
A student achievable synthesis of bisphenol Z, 4,4'-(cyclohexane-1,1-diyl)diphenol, from the acid-catalyzed reaction of phenol with cyclohexanone is presented. The experiment exemplifies all the usual pedagogy for the standard topic of electrophilic aromatic substitution present in the undergraduate organic chemistry curriculum, while providing…
Soap from Nutmeg: An Integrated Introductory Organic Chemistry Laboratory Experiment
NASA Astrophysics Data System (ADS)
de Mattos, Marcio C. S.; Nicodem, David E.
The extraction of trimyristin from nutmeg, its purification, and its conversion to a soap (sodium myristate) are described. Concepts such as the isolation of a natural product, recrystallization, identification of a solid, solubility, acidity and basicity, and organic reaction can be presented to students using integrated experiments in an introductory experimental chemistry laboratory. These experiments can easily be done in three class periods of four hours.
Chemistry 321 Organic Chemistry
Wagner, Diane
Chemistry 321 Organic Chemistry Fall 2010 MWF 1:00-2:00 Reichardt Bldg 202 Instructor: Thomas Dept.) Office Hours: By appointment Required Materials: Organic Chemistry 7th Ed., J. McMurry, Brooks/Cole OWL card RF classroom clicker Recommended: Study Guide & Solutions Manual for Org Chemistry HGS
Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
Smith, Andri L.; Tan, Paula
Students in introductory chemistry classes typically appreciate seeing the connection between course content and the "real world". For this reason, we have developed a synthesis of creatine monohydrate--a popular supplement used in sports requiring short bursts of energy--for introductory organic chemistry laboratory courses. Creatine monohydrate…
Chemistry 675 Advanced Organic Chemistry
Doyle, Robert
Fall 2014 Chemistry 675 Advanced Organic Chemistry MWF 10:35-11:30 AM 200 LSB Professor John D Description: CHE675 is a graduate-level organic chemistry course focused on physical organic chemistry, which in my office (CST 4-006) or my mailbox in the chemistry office (CST 1-014). Late problem sets will have
An Enzyme Kinetics Experiment for the Undergraduate Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Olsen, Robert J.; Olsen, Julie A.; Giles, Greta A.
An experiment using [superscript 1]H NMR spectroscopy to observe the kinetics of the acylase 1-catalyzed hydrolysis of "N"-acetyl-DL-methionine has been developed for the organic laboratory. The L-enantiomer of the reactant is hydrolyzed completely in less than 2 h, and [superscript 1]H NMR spectroscopic data from a single sample can be worked up…
A Cost-Effective Two-Part Experiment for Teaching Introductory Organic Chemistry Techniques
ERIC Educational Resources Information Center
Sadek, Christopher M.; Brown, Brenna A.; Wan, Hayley
This two-part laboratory experiment is designed to be a cost-effective method for teaching basic organic laboratory techniques (recrystallization, thin-layer chromatography, column chromatography, vacuum filtration, and melting point determination) to large classes of introductory organic chemistry students. Students are exposed to different…
Analysis of Analgesic Mixtures: An Organic Chemistry Experiment.
ERIC Educational Resources Information Center
Martin, Ned H.
Describes an experiment to analyze commercial analgesic preparations (pain relievers) by silica gel thin layer chromatography, followed by preparative (thick) layer chromatographic separation and spectroscopic analysis. Key difference from similar experiments is that students are responsible for devising suitable solvent systems for the thin layer…
The Synthesis of a Cockroach Pheromone: An Experiment for the Second-Year Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Feist, Patty L.
This experiment describes the synthesis of gentisyl quinone isovalerate, or blattellaquinone, a sex pheromone of the German cockroach that was isolated and identified in 2005. The synthesis is appropriate for the second semester of a second-year organic chemistry laboratory course. It can be completed in two, three-hour laboratory periods and uses…
The Discovery-Oriented Approach to Organic Chemistry. 7. Rearrangement of "trans"-Stilbene Oxide with Bismuth Trifluoromethanesulfonate and Other Metal Triflates: A Microscale Green Organic Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
Christensen, James E.; Huddle, Matthew G.; Rogers, Jamie L.; Yung, Herbie; Mohan, Ram S.
Although green chemistry principles are increasingly stressed in the undergraduate curriculum, there are only a few lab experiments wherein the toxicity of reagents is taken into consideration in the design of the experiment. We report a microscale green organic chemistry laboratory experiment that illustrates the utility of metal triflates,…
Chemistry 320N Organic Chemistry II
Chemistry 320N Organic Chemistry II for Prehealth Professionals Unique number: 52365 Spring 2013 M students can access the information. #12;Required Text: Brown, Foote, Iverson, & Anslyn Organic Chemistry
The Problem with Organic Chemistry Labs
ERIC Educational Resources Information Center
Mohrig, Jerry R.
The problem with organic chemistry labs is that the educational objectives of lab instructions are often vague and seldom stated. The great majority of organic chemistry labs in American colleges and universities are based on verification experiments.
Organic Chemistry Resources Worldwide
NSDL National Science Digital Library
Van Aken, Koen
Organic Chemistry Worldwide is an excellent organic chemistry metasite that is not to be missed. Geared toward synthetic organic chemists involved in academic or industrial research, Organic Chemistry Resources Worldwide has a mission to collect and independently annotate "all useful organic chemistry sites and to present them in an intuitive way." This extensive metasite is divided into sections on literature, laboratory resources, spectroscopy and spectrometry, nomenclature and teaching, and conferences and organizations. The Literature section contains links to over 75 journals (some restricted access), 14 free databases (and many more commercial), dissertation collections, reviews, guides, patents, and current awareness sources. Examples of resources for laboratory work include links to chemical product databases, laboratory safety bulletins (.pdf), products and services, etc. Highlights of the site are an in-depth section on mass spectrometry, with links to publications and databases, and a plethora of links to organic chemistry labs worldwide, from Armenia to Uruguay.
The Synthesis, Identification, and Kinetic Characterization of the Photoaffinity Label: 3-Azidopyridine Adenosine Dinucleotide: An Advanced Undergraduate Laboratory Experiment Appropriate for Organic, Biochemistry, or Bio-organic Chemistry
We present here a complete photochemical experiment suitable for biochemistry, bioorganic, and organic chemistry laboratories. It provides experiences in chemical and enzymatic syntheses, spectroscopy (IR, NMR, UV), chromatography (TLC, GC-MS), and a simple enzyme kinetic study utilizing UV spectroscopy. The application of light energy to produce chemical changes has recently expanded beyond photography, lithography, and organic synthesis to include use
Use of Protecting Groups in Carbohydrate Chemistry: An Advanced Organic Synthesis Experiment
NASA Astrophysics Data System (ADS)
Cunha, Anna C.; Pereira, Leticia O. R.; de Souza, Maria Cecília B. V.; Ferreira, Vitor F.
A simple and inexpensive three-step reaction sequence for advanced experimental organic chemistry using D-glucosamine hydrochloride as starting material for the synthesis of 2-amino-2-deoxy-1,3,4,6-tetra-O-acetyl-b-D-glucopyranose hydrochloride is described. D-Glucosamine hydrochloride is a carbohydrate derivative isolated from crab shells. It is inexpensive and readily available from most chemical companies. This reaction sequence is appropriate for teaching undergraduate students the correct use of protecting groups. This is a major concept in organic synthesis and one of the determinant factors in the successful realization of multiple-step synthetic projects. The aim of the experiment is to protect the hydroxyl groups of D-glucosamine leaving its amino group as hydrochloride salt. The experiment deals only with protection and deprotection reactions. All products are crystalline substances. The amino group of d-glucosamine hydrochloride is protected by a condensation reaction with p-methoxybenzaldehyde to produce the Schiff's base as a mixture of a- and b-anomers. The second step involves the protection of all hydroxyl groups by esterification reaction using acetic anhydride, forming the imino-tetraacetate derivative as the b-anomer. The stereospecificity of this reaction at the anomeric center is due to the voluminous imino group at C-2. Removal of the amino protection group of this derivative is the final step, which can be accomplished by a selective acid hydrolysis affording the desired peracylated D-glucosamine hydrochloride.
148 Chemistry/Chinese Chemistry 347 (3)--Advanced Organic Chemistry
Dresden, Gregory
,organometalliccatalyticprocesses,andsolid statechemistry.Uffelman. Spring 2008 and alternate years Chemistry 365 (3)--Advanced Physical Chemistry148 Chemistry/Chinese Chemistry 347 (3)--Advanced Organic Chemistry Prerequisite: Chemistry 242,syntheticmethodology,mod- ernsyntheticreactions,protectinggroups,naturalprod- uctssynthesis,andcombinatorialchemistry.France. Spring Chemistry
SYLLABUS for CHEMISTRY 2310 ORGANIC CHEMISTRY 1
Simons, Jack
SYLLABUS for CHEMISTRY 2310 ORGANIC CHEMISTRY 1 Lectures: Monday, Wednesday and Friday 8:35 AM-9 Chemistry" by Janice Gorzynski Smith, McGraw Hill, 3rd Edition, 2010 [2nd Edition will suffice]. The ebook · Highly Recommended Equipment: Turning Point Clicker · Highly Recommended: (1) "Organic Chemistry I
CHEMISTRY DEPARTMENT Chem 315 (Honors Organic Chemistry)
Lawson, Catherine L.
CHEMISTRY DEPARTMENT Chem 315 (Honors Organic Chemistry) Fall 2014 Important Registration Information Admission to Honors Organic Chemistry (Fall 2014) is restricted to the following students: Students who received an A in both semesters of General Chemistry (159 and 160 OR 161 and 162 OR 163
Extraction and [superscript 1]H NMR Analysis of Fats from Convenience Foods: A Laboratory Experiment for Organic Chemistry
ERIC Educational Resources Information Center
Hartel, Aaron M.; Moore, Amy C.
The extraction and analysis of fats from convenience foods (crackers, cookies, chips, candies) has been developed as an experiment for a second-year undergraduate organic chemistry laboratory course. Students gravimetrically determine the fat content per serving and then perform a [superscript 1]H NMR analysis of the recovered fat to determine the…
NSDL National Science Digital Library
ChemWeb's Organic Chemistry Forum bills itself as a "free online club for the organic chemistry community." Users will need to complete a simple online form to obtain membership and access the site. One highlight of this site is free full-text access to Tetrahedron Letters. This rapid publication journal appears weekly. Along with free access to Beilstein Abstracts, the site includes jobs, a conference diary, news, discussion groups, and more.
NSDL National Science Digital Library
ChemWeb's Organic Chemistry Forum bills itself as a "free online club for the organic chemistry community." Users will need to complete a simple online form to obtain membership and access the site. One highlight of this site is free full-text access to Tetrahedron Letters. This rapid publication journal appears weekly. Along with free access to Beilstein Abstracts, the site includes jobs, a conference diary, news, discussion groups, and more.
Exploring Atmospheric Aqueous Chemistry (and Secondary Organic Aerosol Formation) through OH Radical Oxidation Experiments, Droplet Evaporation and Chemical Modeling
NASA Astrophysics Data System (ADS)
Turpin, B. J.; Kirkland, J. R.; Lim, Y. B.; Ortiz-Montalvo, D. L.; Sullivan, A.; Häkkinen, S.; Schwier, A. N.; Tan, Y.; McNeill, V. F.; Collett, J. L.; Skog, K.; Keutsch, F. N.; Sareen, N.; Carlton, A. G.; Decesari, S.; Facchini, C.
Gas phase photochemistry fragments and oxidizes organic emissions, making water-soluble organics ubiquitous in the atmosphere. My group and others have found that several water-soluble compounds react further in the aqueous phase forming low volatility products under atmospherically-relevant conditions (i.e., in clouds, fogs and wet aerosols). Thus, secondary organic aerosol can form as a result of gas followed by aqueous chemistry (aqSOA). We have used aqueous OH radical oxidation experiments coupled with product analysis and chemical modeling to validate and refine the aqueous chemistry of glyoxal, methylglyoxal, glycolaldehyde, and acetic acid. The resulting chemical model has provided insights into the differences between oxidation chemistry in clouds and in wet aerosols. Further, we conducted droplet evaporation experiments to characterize the volatility of the products. Most recently, we have conducted aqueous OH radical oxidation experiments with ambient mixtures of water-soluble gases to identify additional atmospherically-important precursors and products. Specifically, we scrubbed water-soluble gases from the ambient air in the Po Valley, Italy using four mist chambers in parallel, operating at 25-30 L min-1. Aqueous OH radical oxidation experiments and control experiments were conducted with these mixtures (total organic carbon ? 100 ?M-C). OH radicals (3.5E-2 ?M [OH] s-1) were generated by photolyzing H2O2. Precursors and products were characterized using electrospray ionization mass spectrometry (ESI-MS), ion chromatography (IC), IC-ESI-MS, and ultra high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Chemical modeling suggests that organic acids (e.g., oxalate, pyruvate, glycolate) are major products of OH radical oxidation at cloud-relevant concentrations, whereas organic radical - radical reactions result in the formation of oligomers in wet aerosols. Products of cloud chemistry and droplet evaporation have effective vapor pressures that are orders of magnitude lower when ammonium hydroxide is present (pH 7) than without (at lower pH). In Po Valley experiments, nitrogen-containing organics were prominent precursors and intermediates. Pyruvate and oxalate were among the products. Importantly, formation of aqSOA helps to explain the high O/C ratios found in atmospheric aerosols. While uncertainties remain large, global modeling suggests that aqSOA is comparable in magnitude to SOA formed through gas phase chemistry and vapor pressure driven partitioning (gasSOA).
UCLA: Organic Chemistry Tutorials
NSDL National Science Digital Library
Hardinger, Steven
Steven Hardinger at the Department of Chemistry and Biochemistry at UCLA created these tutorials to assist students with the difficult concepts presented in introductory organic chemistry. Students can find tutorials dealing with acids and bases, carbocations, Lewis dot structures, and more. Within each tutorial, users can find links to a dictionary that adequately explain the unfamiliar terminology. The tutorials include example problems and exercises to challenge users.
Perspectives on Computational Organic Chemistry
Streitwieser, Andrew
The author reviews how his early love for theoretical organic chemistry led to experimental research and the extended search for quantitative correlations between experiment and quantum calculations. The experimental work led to ion pair acidities of alkali-organic compounds and most recently to equilibria and reactions of lithium and cesium enolates in THF. This chemistry is now being modeled by ab initio calculations. An important consideration is the treatment of solvation in which coordination of the alkali cation with the ether solvent plays a major role. PMID:19518150
Wagner, Diane
1 Fall 2010 CHEMISTRY 324W ORGANIC LABORATORY Course Information Title: Chemistry 324W, Organic for multiple chemistry classes) $5 key deposit fee (refunded at end of semester with return of key) Course a scientific paper consistent with the format of the Journal of Organic Chemistry, American Chemical Society. 7
NASA Technical Reports Server (NTRS)
Charnley, Steven
Astronomical observations, theoretical modeling, laboratory simulation and analysis of extraterrestrial material have enhanced our knowledge of the inventory of organic matter in the interstellar medium (ISM) and on small bodies such as comets and asteroids (Ehrenfreund & Charnley 2000). Comets, asteroids and their fragments, meteorites and interplanetary dust particles (IDPs), contributed significant amounts of extraterrestrial organic matter to the young Earth. This material degraded and reacted in a terrestrial prebiotic chemistry to form organic structures that may have served as building blocks for life on the early Earth. In this talk I will summarize our current understanding of the organic composition and chemistry of interstellar clouds. Molecules of astrobiological relevance include the building blocks of our genetic material: nucleic acids, composed of subunits such as N-heterocycles (purines and pyrimidines), sugars and amino acids. Signatures indicative of inheritance of pristine and modified interstellar material in comets and meteorites will also be discussed.
ERIC Educational Resources Information Center
Janowicz, Philip A.
This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…
The 1953 Stanley L. Miller Experiment: Fifty Years of Prebiotic Organic Chemistry
NASA Technical Reports Server (NTRS)
Lazcano, Antonio; Bada, Jeffrey L.
The field of prebiotic chemistry effectively began with a publication in Science 50 years ago by Stanley L. Miller on the spark discharge synthesis of amino acids and other compounds using a mixture of reduced gases that were thought to represent the components of the atmosphere on the primitive Earth. On the anniversary of this landmark publication, we provide here an accounting of the events leading to the publication of the paper. We also discuss the historical aspects that lead up to the landmark Miller experiment.
NSDL National Science Digital Library
Students who might be puzzled by the world of organic chemistry will definitely want to bookmark this useful site created by a team of researchers at the University of Liverpool. The site focuses on providing interactive 3D animations for a number of important organic reactions that will be encountered by students taking organic chemistry. The site's homepage contains a list of recent updates and additions, and visitors will want to also look at the list of reactions covered on the left-hand side of the same page. After clicking on each reaction, visitors can view the animation and also click on the animation to view additional resources. For those who are looking for specific reactions, the site also contains an embedded search engine feature.
Organic Chemistry, 5th Edition
NSDL National Science Digital Library
Finds ChemEd DL resources related to the sections of the Organic Chemistry textbook, Organic Chemistry, 5th Edition, by William H. Brown, Christopher S. Foote, Brent L. Iverson, Eric Anslyn published by Brooks/Cole, 2009.
The Birthday of Organic Chemistry.
ERIC Educational Resources Information Center
Benfey, Otto Theodor; Kaufman, George B.
Describes how the synthesis of urea, 150 years ago, was a major factor in breaking the artificial barrier that existed between organic and inorganic chemistry, and this contributed to the rapid growth of organic chemistry. (GA)
Computational organic chemistry: bridging theory and experiment in establishing the mechanisms of chemical reactions.
Cheng, Gui-Juan; Zhang, Xinhao; Chung, Lung Wa; Xu, Liping; Wu, Yun-Dong
Understanding the mechanisms of chemical reactions, especially catalysis, has been an important and active area of computational organic chemistry, and close collaborations between experimentalists and theorists represent a growing trend. This Perspective provides examples of such productive collaborations. The understanding of various reaction mechanisms and the insight gained from these studies are emphasized. The applications of various experimental techniques in elucidation of reaction details as well as the development of various computational techniques to meet the demand of emerging synthetic methods, e.g., C-H activation, organocatalysis, and single electron transfer, are presented along with some conventional developments of mechanistic aspects. Examples of applications are selected to demonstrate the advantages and limitations of these techniques. Some challenges in the mechanistic studies and predictions of reactions are also analyzed. PMID:25568962
NASA Technical Reports Server (NTRS)
Chang, S.; Scattergood, T.; Aronowitz, S.; Flores, J.
Features taken from various models of Titan's atmosphere are combined in a working composite model that provides environmental constraints within which different pathways for organic chemical synthesis are determined. Experimental results and theoretical modeling suggest that the organic chemistry of the satellite is dominated by two processes: photochemistry and energetic particle bombardment. Photochemical reactions of CH4 in the upper atmosphere can account for the presence of C2 hydrocarbons. Reactions initiated at various levels of the atmosphere by cosmic rays, Saturn 'wind', and solar wind particle bombardment of a CH4-N2 atmospheric mixture can account for the UV-visible absorbing stratospheric haze, the reddish appearance of the satellite, and some of the C2 hydrocarbons. In the lower atmosphere photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. It is concluded that the surface of Titan may contain ancient or recent organic matter (or both) produced in the atmosphere.
Improving the Effectiveness of Organic Chemistry Experiments through Multimedia Teaching Materials for Junior High School Students
ERIC Educational Resources Information Center
Lou, Shi-Jer; Lin, Hui-Chen; Shih, Ru-Chu; Tseng, Kuo-Hung
The purpose of the study aimed to explore the effects of three different forms of the multimedia teaching materials on the achievements and attitudes of junior high school students in a chemistry laboratory context. The three forms of the multimedia teaching materials, static pictures, video, and animation, were employed to teach chemistry…
Organic Chemistry and Your Cellphone
NSDL National Science Digital Library
Hooley, Richard J.
The National Center for Case Study Teaching in Science releases new and helpful teaching materials on a regular basis. This recent addition to the Center's great resources deals with organic chemistry and cellphones. Crafted by Courtney Meyet and Richard Hooley of the University of California, Riverside, this case study guides students "through a systematic exploration of the synthesis and properties of polyphenylene vinylene." The whole experience starts with a classic article from Nature magazine and includes a PowerPoint presentation, a series of group questions, and other activities. The resources here are intended for an undergraduate audience and persons with an interest in organic reactions, organic materials, and polymers will find that this resource is most efficacious.
Mars aqueous chemistry experiment
NASA Technical Reports Server (NTRS)
Clark, Benton C.; Mason, Larry W.
The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.
Organic Chemistry for the Gifted.
ERIC Educational Resources Information Center
deBeer, W. H. J.
In response to a serious shortage of chemists in South Africa, gifted secondary school students are enrolled in an enrichment program in organic chemistry and encouraged to consider chemistry or one of its related fields as a career. The introductory portion of the program involves approximately 90 hours over a 3-year period while the advanced…
Like Dissolves Like: A Classroom Demonstration and a Guided-Inquiry Experiment for Organic Chemistry.
ERIC Educational Resources Information Center
Montes, Ingrid; Lai, Chunqiu; Sanabria, David
Describes a classroom demonstration supported by the guided-inquiry experience that focuses on separation techniques and other solvent-dependent processes, such as reaction-solvent selection. (Contains 13 references.) (YDS)
Synthesis of Chemiluminescent Esters: A Combinatorial Synthesis Experiment for Organic Chemistry Students
ERIC Educational Resources Information Center
Duarte, Robert; Nielson, Janne T.; Dragojlovic, Veljko
A group of techniques aimed at synthesizing a large number of structurally diverse compounds is called combinatorial synthesis. Synthesis of chemiluminescence esters using parallel combinatorial synthesis and mix-and-split combinatorial synthesis is experimented.
Undergraduate Organic Chemistry Laboratory Safety
NASA Astrophysics Data System (ADS)
Luckenbaugh, Raymond W.
Each organic chemistry student should become familiar with the educational and governmental laboratory safety requirements. One method for teaching laboratory safety is to assign each student to locate safety resources for a specific class laboratory experiment. The student should obtain toxicity and hazardous information for all chemicals used or produced during the assigned experiment. For example, what is the LD50 or LC50 for each chemical? Are there any specific hazards for these chemicals, carcinogen, mutagen, teratogen, neurotixin, chronic toxin, corrosive, flammable, or explosive agent? The school's "Chemical Hygiene Plan", "Prudent Practices for Handling Hazardous Chemicals in the Laboratory" (National Academy Press), and "Laboratory Standards, Part 1910 - Occupational Safety and Health Standards" (Fed. Register 1/31/90, 55, 3227-3335) should be reviewed for laboratory safety requirements for the assigned experiment. For example, what are the procedures for safe handling of vacuum systems, if a vacuum distillation is used in the assigned experiment? The literature survey must be submitted to the laboratory instructor one week prior to the laboratory session for review and approval. The student should then give a short presentation to the class on the chemicals' toxicity and hazards and describe the safety precautions that must be followed. This procedure gives the student first-hand knowledge on how to find and evaluate information to meet laboartory safety requirements.
Bioactivity in Organic Chemistry Courses.
ERIC Educational Resources Information Center
Ferguson, Lloyd N.
Presented are three ways in which bioactivity of organic compounds has been introduced in organic chemistry courses. One is to point out a typical bioactivity of a given functional group. A second is to discuss biorganic mechanisms. A third is to draw structure-activity correlations (SAR). (Author/HM)
Mass spectrometry. [in organic chemistry
NASA Technical Reports Server (NTRS)
Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.
A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.
Mars aqueous chemistry experiment
NASA Technical Reports Server (NTRS)
Clark, Benton C.; Mason, Larry W.
Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.
NASA Technical Reports Server (NTRS)
Johnson, R. D.
Organic cosmochemistry, organic materials in space exploration, and biochemistry of man in space are briefly surveyed. A model of Jupiter's atmosphere is considered, and the search for organic molecules in the solar system and in interstellar space is discussed. Materials and analytical techniques relevant to space exploration are indicated, and the blood and urine analyses performed on Skylab are described.
NASA Technical Reports Server (NTRS)
Sagan, C.; Thompson, W. R.; Khare, B. N.
Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of the simulated Titanian atmosphere, are consistent with measured properties of Titan from ultraviolet to microwave frequencies and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on earth. At least 100-m, and possibly kms thicknesses of complex organics have been produced on Titan during the age of the solar system, and may exist today as submarine deposits beneath an extensive ocean of simple hydrocarbons.
ERIC Educational Resources Information Center
Anderson, G.
A brief review is presented of some of the organic compounds and reactions that occur in soil. Included are nitrogenous compounds, compounds of phosphorus and sulfur, carbohydrates, phenolic compounds, and aliphatic acids. (BB)
Interstellar organic chemistry.
NASA Technical Reports Server (NTRS)
Sagan, C.
Most of the interstellar organic molecules have been found in the large radio source Sagittarius B2 toward the galactic center, and in such regions as W51 and the IR source in the Orion nebula. Questions of the reliability of molecular identifications are discussed together with aspects of organic synthesis in condensing clouds, degradational origin, synthesis on grains, UV natural selection, interstellar biology, and contributions to planetary biology.
Organic Chemistry of Meteorites
NASA Technical Reports Server (NTRS)
Chang, S.; Morrison, David (Technical Monitor)
Studies of the molecular structures and C,N,H-isotopic compositions of organic matter in meteorites reveal a complex history beginning in the parent interstellar cloud which spawned the solar system. Incorporation of interstellar dust and gas in the protosolar nebula followed by further thermal and aqueous processing on primordial parent bodies of carbonaceous, meteorites have produced an inventory of diverse organic compounds including classes now utilized in biochemistry. This inventory represents one possible set of reactants for chemical models for the origin of living systems on the early Earth. Evidence bearing on the history of meteoritic organic matter from astronomical observations and laboratory investigations will be reviewed and future research directions discussed.
Radiation Chemistry in Organized Assemblies.
ERIC Educational Resources Information Center
Thomas, J. K.; Chen, T. S.
Expands the basic concepts regarding the radiation chemistry of simple aqueous systems to more complex, but well defined, organized assemblies. Discusses the differences in behavior in comparison to simple systems. Reviews these techniques: pulse radiolysis, laser flash, photolysis, and steady state irradiation by gamma rays or light. (CS)
Titan: a laboratory for prebiological organic chemistry
NASA Technical Reports Server (NTRS)
Sagan, C.; Thompson, W. R.; Khare, B. N.
When we examine the atmospheres of the Jovian planets (Jupiter, Saturn, Uranus, and Neptune), the satellites in the outer solar system, comets, and even--through microwave and infrared spectroscopy--the cold dilute gas and grains between the stars, we find a rich organic chemistry, presumably abiological, not only in most of the solar system but throughout the Milky Way galaxy. In part because the composition and surface pressure of the Earth's atmosphere 4 x 10(9) years ago are unknown, laboratory experiments on prebiological organic chemistry are at best suggestive; but we can test our understanding by looking more closely at the observed extraterrestrial organic chemistry. The present Account is restricted to atmospheric organic chemistry, primarily on the large moon of Saturn. Titan is a test of our understanding of the organic chemistry of planetary atmospheres. Its atmospheric bulk composition (N2/CH4) is intermediate between the highly reducing (H2/He/CH4/NH3/H2O) atmospheres of the Jovian planets and the more oxidized (N2/CO2/H2O) atmospheres of the terrestrial planets Mars and Venus. It has long been recognized that Titan's organic chemistry may have some relevance to the events that led to the origin of life on Earth. But with Titan surface temperatures approximately equal to 94 K and pressures approximately equal to 1.6 bar, the oceans of the early Earth have no ready analogue on Titan. Nevertheless, tectonic events in the water ice-rich interior or impact melting and slow re-freezing may lead to an episodic availability of liquid water. Indeed, the latter process is the equivalent of a approximately 10(3)-year-duration shallow aqueous sea over the entire surface of Titan.
Titan: a laboratory for prebiological organic chemistry.
Sagan, C; Thompson, W R; Khare, B N
When we examine the atmospheres of the Jovian planets (Jupiter, Saturn, Uranus, and Neptune), the satellites in the outer solar system, comets, and even--through microwave and infrared spectroscopy--the cold dilute gas and grains between the stars, we find a rich organic chemistry, presumably abiological, not only in most of the solar system but throughout the Milky Way galaxy. In part because the composition and surface pressure of the Earth's atmosphere 4 x 10(9) years ago are unknown, laboratory experiments on prebiological organic chemistry are at best suggestive; but we can test our understanding by looking more closely at the observed extraterrestrial organic chemistry. The present Account is restricted to atmospheric organic chemistry, primarily on the large moon of Saturn. Titan is a test of our understanding of the organic chemistry of planetary atmospheres. Its atmospheric bulk composition (N2/CH4) is intermediate between the highly reducing (H2/He/CH4/NH3/H2O) atmospheres of the Jovian planets and the more oxidized (N2/CO2/H2O) atmospheres of the terrestrial planets Mars and Venus. It has long been recognized that Titan's organic chemistry may have some relevance to the events that led to the origin of life on Earth. But with Titan surface temperatures approximately equal to 94 K and pressures approximately equal to 1.6 bar, the oceans of the early Earth have no ready analogue on Titan. Nevertheless, tectonic events in the water ice-rich interior or impact melting and slow re-freezing may lead to an episodic availability of liquid water. Indeed, the latter process is the equivalent of a approximately 10(3)-year-duration shallow aqueous sea over the entire surface of Titan. PMID:11537156
Molecular Modelling for Organic Chemistry
NSDL National Science Digital Library
The Department of Chemistry at Imperial College of Science, Technology and Medicine provides the Molecular Modelling for Organic Chemistry Website. Molecular modelling is defined as a "technique for deriving, representing and manipulating the structures and reactions of molecules, and those properties that are dependent on these three dimensional structures." This site aims to help users learn which molecular modelling tool is appropriate for a typical problem depending on structure, activity or reactivity, and the limitations and strengths of each method. Sections included at the site are Introduction, Overview, the various Case Studies (1-12), Transition State WS, Course Problems, and Available Modelling Programs. A list of related links rounds out the site.
NSDL National Science Digital Library
Nowick, James
The OpenCourseWare Initiative has brought hundreds of course materials to people from Indonesia to Indiana. The University of California, Irvine has a number of excellent materials, one of which is this particular course offering. This course in organic chemistry was created by Professor James Nowick. On the site, visitors can view 27 different lectures from the fall 2009 iteration of the course. In addition, they can work through the assigned chapters in the textbook (not available on the website) to deepen their problem-solving skills. The topics covered here include resonance structures, organic compounds, and the properties of chiral compounds. The course materials will be quite useful to persons studying organic chemistry, or for those people who may need a refresher as part of their professional development.
NSDL National Science Digital Library
Nowick, James
The OpenCourseWare Initiative has brought hundreds of course materials to people from Indonesia to Indiana. The University of California, Irvine has a number of excellent materials, one of which is this particular course offering. This course in organic chemistry was created by Professor James Nowick. On the site, visitors can view 27 different lectures from the fall 2009 iteration of the course. In addition, they can work through the assigned chapters in the textbook (not available on the website) to deepen their problem-solving skills. The topics covered here include resonance structures, organic compounds, and the properties of chiral compounds. The course materials will be quite useful to persons studying organic chemistry, or for those people who may need a refresher as part of their professional development.
Reaction-Map of Organic Chemistry
ERIC Educational Resources Information Center
Murov, Steven
The Reaction-Map of Organic Chemistry lists all the most commonly studied reactions in organic chemistry on one page. The discussed Reaction-Map will act as another learning aide for the students, making the study of organic chemistry much easier.
Medicinal Chemistry/Pharmacology in Sophomore Organic Chemistry.
ERIC Educational Resources Information Center
Harrison, Aline M.
Discussed is a series of lectures designed to illustrate the use of general organic chemical principles in molecular biology, introduce current research in interdisciplinary areas to the beginner, increase interest in organic chemistry, and bridge the gap between traditional organic chemistry, biology, and the consumer. An outline is presented.…
Headspace GC-MS Analysis of Halogenated Volatile Organic Compounds in Aqueous Samples: An Experiment for General Chemistry Laboratory
ERIC Educational Resources Information Center
Keller, John W.; Fabbri, Cindy E.
Analysis of halogenated volatile organic compounds (HVOCs) by GC-MS demonstrates the use of instrumentation in the environmental analysis of pollutant molecules and enhances student understanding of stable isotopes in nature. In this experiment, students separated and identified several HVOCs that have been implicated as industrial groundwater…
Chemistry of Organic Electronic Materials 6483-Fall
Sherrill, David
Chemistry of Organic Electronic Materials 6483- Fall Tuesdays organic materials. The discussion will include aspects of synthesis on Organic Photonics and Electronics at Georgia Tech) and of an ultra-thin 55
The experiments in this course are examples of real-life problems which make use of organic chemistry in various ways and have impact on diverse businesses and industries. Each
Houston, Paul L.
Overview The experiments in this course are examples of real-life problems which make use of organic chemistry in various ways and have impact on diverse businesses and industries. Each experiment participants have been changed! The aim of each experiment is for you to provide a solution to the problem
Caring for the Environment while Teaching Organic Chemistry
ERIC Educational Resources Information Center
Santos, Elvira Santos; Gavilan Garcia, Irma Cruz; Lejarazo Gomez, Eva Florencia
A comprehensive program in the field of green chemistry, which concentrates on processing and managing of wastes produced during laboratory experiments, is presented. The primary aim of the program is to instill a sense of responsibility and a concern for the environment through organic chemistry education.
A Multistep Synthesis for an Advanced Undergraduate Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Chang Ji; Peters, Dennis G.
Multistep syntheses are often important components of the undergraduate organic laboratory experience and a three-step synthesis of 5-(2-sulfhydrylethyl) salicylaldehyde was described. The experiment is useful as a special project for an advanced undergraduate organic chemistry laboratory course and offers opportunities for students to master a…
Incorporation of Medicinal Chemistry into the Organic Chemistry Curriculum
ERIC Educational Resources Information Center
Forbes, David C.
Application of concepts presented in organic chemistry lecture using a virtual project involving the sythesis of medicinally important compounds is emphasized. The importance of reinforcing the concepts from lecture in lab, thus providing a powerful instructional means is discussed.
American Chemical Society: Division of Organic Chemistry
NSDL National Science Digital Library
Established in 1908, the American Chemical Society (ACS) Organic Chemistry Division created this website to illustrate its work to cultivate and promote the advancement of the field of organic chemistry. Researchers can learn about upcoming meetings and conferences. Chemistry students and educators can learn about fellowship, awards, and employment opportunities. The website provides an extensive list of links to scientific journals. Visitors can also learn about membership benefits and how to join the group.
Organic Chemistry at University College, London
W. J. Pope
IT is now an open secret that the Academic Council of the University of London is being moved not to appoint an eminent organic chemist to succeed Prof. Robinson in the chair of organic chemistry in University College, London, but to fill the two chairs of chemistry in this institution by distinguished physical chemists. The acceptance of such a fantastic
Understanding Academic Performance in Organic Chemistry
ERIC Educational Resources Information Center
Szu, Evan; Nandagopal, Kiruthiga; Shavelson, Richard J.; Lopez, Enrique J.; Penn, John H.; Scharberg, Maureen; Hill, Geannine W.
Successful completion of organic chemistry is a prerequisite for many graduate and professional programs in science, technology, engineering, and mathematics, yet the failure rate for this sequence of courses is notoriously high. To date, few studies have examined why some students succeed while others have difficulty in organic chemistry. This…
The Wittig Reaction: Generation, Observation and Reactivity of a Phosphorous Ylide Intermediate. An Experiment for the Advanced Organic Chemistry Laboratory Course
NASA Astrophysics Data System (ADS)
Breton, Gary W.
An experiment has been devised that illustrates three important concepts in organic chemistry: the synthesis of an alkene via the Wittig reaction, characterization of a reactive intermediate by 1H NMR, and site - specific deuterium labelling. Deprotonation of ethyltriphenylphosphonium iodide (1) by methylsulfinyl carbanion (generated in situ by the reaction of NaH with DMSO-d6) results in the formation of the ylide, CH3CH-PPH3(2 -H). An ensuing, rapid deuterium exchange process between the deuterated solvent, and 2-H at the C-1 position affords CH3CD - PPH3 (2-D). The 1H NMR spectrum of 2-D was obtained, and the ylide was quenched with benzophenone to obtain 2-deutero-diphenylpropene (3) in 42% yield.
Interdisciplinary Chemistry Experiment: An Environmentally Friendly Extraction of Lycopene
ERIC Educational Resources Information Center
Zhu, Jie; Zhang, Mingjie; Liu, Qingwei
A novel experiment for the extraction of lycopene from tomato paste without the use of an organic solvent is described. The experiment employs polymer, green, and analytical chemistry. This environmentally friendly extraction is more efficient and requires less time than the traditional approach using an organic solvent. The extraction is…
Mechanochemical Synthesis of Two Polymorphs of the Tetrathiafulvalene-Chloranil Charge Transfer Salt: An Experiment for Organic Chemistry
ERIC Educational Resources Information Center
Wixtrom, Alex; Buhler, Jessica; Abdel-Fattah, Tarek
Mechanochemical syntheses avoid or considerably reduce the use of reaction solvents, thus providing green chemistry synthetic alternatives that are both environmentally friendly and economically advantageous. The increased solid-state reactivity generated by mechanical energy imparted to the reactants by grinding or milling can offer alternative…
Green chemistry oriented organic synthesis in water.
Simon, Marc-Olivier; Li, Chao-Jun
The use of water as solvent features many benefits such as improving reactivities and selectivities, simplifying the workup procedures, enabling the recycling of the catalyst and allowing mild reaction conditions and protecting-group free synthesis in addition to being benign itself. In addition, exploring organic chemistry in water can lead to uncommon reactivities and selectivities complementing the organic chemists' synthetic toolbox in organic solvents. Studying chemistry in water also allows insight to be gained into Nature's way of chemical synthesis. However, using water as solvent is not always green. This tutorial review briefly discusses organic synthesis in water with a Green Chemistry perspective. PMID:22048162
Preparation, Characterization, and Postsynthetic Modification of Metal-Organic Frameworks: Synthetic Experiments for an Undergraduate Laboratory Course in Inorganic Chemistry
ERIC Educational Resources Information Center
Sumida, Kenji; Arnold, John
Metal-organic frameworks (MOFs) are crystalline materials that are composed of an infinite array of metal nodes (single ions or clusters) linked to one another by polyfunctional organic compounds. Because of their extraordinary surface areas and high degree of control over the physical and chemical properties, these materials have received much…
A Discovery Chemistry Experiment on Buffers
ERIC Educational Resources Information Center
Kulevich, Suzanne E.; Herrick, Richard S.; Mills, Kenneth V.
The Holy Cross Chemistry Department has designed and implemented an experiment on buffers as part of our Discovery Chemistry curriculum. The pedagogical philosophy of Discovery Chemistry is to make the laboratory the focal point of learning for students in their first two years of undergraduate instruction. We first pose questions in prelaboratory…
Customized Laboratory Experience in Physical Chemistry
ERIC Educational Resources Information Center
Castle, Karen J.; Rink, Stephanie M.
A new physical chemistry laboratory experience has been designed for upper-level undergraduate chemistry majors. Students customize the first 10 weeks of their laboratory experience by choosing their own set of experiments (from a manual of choices) and setting their own laboratory schedule. There are several topics presented in the accompanying…
A Colorful Solubility Exercise for Organic Chemistry
ERIC Educational Resources Information Center
Shugrue, Christopher R.; Mentzen, Hans H., II; Linton, Brian R.
A discovery chemistry laboratory has been developed for the introductory organic chemistry student to investigate the concepts of polarity, miscibility, solubility, and density. The simple procedure takes advantage of the solubility of two colored dyes in a series of solvents or solvent mixtures, and the diffusion of colors can be easily…
Oxidation of Borneol to Camphor Using Oxone and Catalytic Sodium Chloride: A Green Experiment for the Undergraduate Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Lang, Patrick T.; Harned, Andrew M.; Wissinger, Jane E.
A new green oxidation procedure was developed for the undergraduate organic teaching laboratories using Oxone and a catalytic quantity of sodium chloride for the conversion of borneol to camphor. This simple 1 h, room temperature reaction afforded high quality and yield of product, was environmentally friendly, and produced negligible quantities…
Chemistry Experiments: Chemistry Challenge for Kids Ages 5 Through 12
NSDL National Science Digital Library
Sciencenter of Ithaca, New York
These chemistry experiments for younger students, from the Sciencenter of Ithaca, New York, can be performed as demonstrations by the teacher, at home, or by the students themselves. These experiments, which investigate the properties of chemicals to solve puzzles or challenges, focus on creating electrical current, color-changing solutions, reactions that involve heat loss or gain, identifying unknowns, and other matters. Each is available in downloadable, printable format (PDF) and includes objectives, materials lists, instructions, safety tips, and other information. Other documents include lists of all the experiments, instructions for a take-home chemistry kit, and downloadable, printable signs to be used with the experiments.
Analysis of Bromination of Ethylbenzene Using a 45 MHz NMR Spectrometer: An Undergraduate Organic Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
Isaac-Lam, Meden F.
A 45 MHz benchtop NMR spectrometer is used to identify the structures and determine the amount of 1-bromoethylbenzene and 1,1-dibromoethylbenzene produced from free-radical bromination of ethylbenzene. The experiment is designed for nonchemistry majors, specifically B.S. Biology students, in a predominantly undergraduate institution with…
Preparation of a N-Heterocyclic Carbene Nickel(II) Complex: Synthetic Experiments in Current Organic and Organometallic Chemistry
ERIC Educational Resources Information Center
Ritleng, Vincent; Brenner, Eric; Chetcuti, Michael J.
A four-part experiment that leads to the synthesis of a cyclopentadienyl chloro-nickel(II) complex bearing a N-heterocyclic carbene (NHC) ligand is presented. In the first part, the preparation of 1,3-bis-(2,4,6-trimethylphenyl)imidazolium chloride (IMes[middle dot]HCl) in a one-pot procedure by reaction of 2,4,6-trimethylaniline with…
Mars Aqueous Chemistry Experiment (MACE)
NASA Technical Reports Server (NTRS)
Benton, Clark C. (Editor)
The concept of an aqueous-based chemical analyzer for Martian surface materials has been demonstrated to be feasible. During the processes of analysis, design, breadboarding, and most importantly, testing, it has become quite apparent that there are many challenges in implementing such a system. Nonetheless, excellent progress has been made and a number of problems which arose have been solved. The ability to conduct this work under a development environment which is separate and which precedes the project-level development has allowed us to find solutions to these implementation realities at low cost. If the instrument had been selected for a mission without this laboratory pre-project work, the costs of implementation would be much higher. In the four areas covered in Sections D, E, F, and G of this Final Report, outstanding progress has been made. There still remains the task of flight-qualifying certain of the components. This is traditionally done under the aegis of a Flight Project, but just as the concept development can be done at much lower cost when kept small and focused, so could the qualification program of critical parts benefit. We recommend, therefore, that NASA consider means of such qualifications and brass-boarding, in advance of final flight development. This is a generic recommendation, but hardware such as the Mars aqueous chemistry experiment (MACE) and other similarly-new concepts are particularly applicable. MACE now has wide versatility, in being able to reliably dispense both liquids and solids as chemical reagents to an entire suite of samples. The hardware and the experiment is much simpler than was developed for the Viking Biology instrument, yet can accomplish all the inorganic chemical measurements that the Viking desing was capable of. In addition, it is much more flexible and versatile to new experiment protocols (and reagents) than the Viking design ever could have been. MACE opens up the opportunity for many different scientific disciplines to design sub- experiments and to benefit from the investigations that can be conducted. In this sense, it will have the value of a facility, although our recommendation would be that it be under the stewardship of a single lead investigator to insure that conflicting requirements not compromise the straight-forward design that have been achieved. MACE is an excellent candidate for upcoming Mars missions, including the Mars Surveyor Program (MSP) lander missions in 2001 and 2003. In addition, it could be used for any mission to the surface of any other planet or planetary body (including small bodies). An important next step is to encourage various investigators to propose specific uses for this experiment that specifically address their major scientific objectives for upcoming missions.
Organic chemistry in Titan's atmosphere
NASA Technical Reports Server (NTRS)
Scattergood, T.
Laboratory photochemical simulations and other types of chemical simulations are discussed. The chemistry of methane, which is the major known constituent of Titan's atmosphere was examined with stress on what can be learned from photochemistry and particle irradiation. The composition of dust that comprises the haze layer was determined. Isotope fractionation in planetary atmospheres is also discussed.
The 'wired' universe of organic chemistry.
Grzybowski, Bartosz A; Bishop, Kyle J M; Kowalczyk, Bartlomiej; Wilmer, Christopher E
The millions of reactions performed and compounds synthesized by organic chemists over the past two centuries connect to form a network larger than the metabolic networks of higher organisms and rivalling the complexity of the World Wide Web. Despite its apparent randomness, the network of chemistry has a well-defined, modular architecture. The network evolves in time according to trends that have not changed since the inception of the discipline, and thus project into chemistry's future. Analysis of organic chemistry using the tools of network theory enables the identification of most 'central' organic molecules, and for the prediction of which and how many molecules will be made in the future. Statistical analyses based on network connectivity are useful in optimizing parallel syntheses, in estimating chemical reactivity, and more. PMID:21378798
BOMC LabBOMC Lab (Bio(Bio--Organic Materials Chemistry)Organic Materials Chemistry)
Jonas, Ulrich - Institute of Electronic Structure and Laser, Foundation for Research and Technology
BOMC LabBOMC Lab (Bio(Bio--Organic Materials Chemistry)Organic Materials Chemistry) FORTHFORTHSystems BioBio--PolymerPolymer HybridHybrid SystemsSystems PolymericPolymeric Particles &Particles & Thin. Phys. A 2008 #12;BioBio--PolymerPolymer NanoreactorsNanoreactors #12;BioBio--Polymer Hybrid Systems
The role of organic complexation on ambient iron chemistry in the equatorial Pacific Ocean and the response of a mesoscale iron addition experiment
Eden L. Rue
We participated on the Iron-Ex II study in the equatorial Pacific to investigate ambient iron chemistry and its response to a mesoscale iron addition experiment. As expected, dissolved iron values in the high-nutrient, low- chlorophyll surface waters of the South Equatorial Current (4-6\\
Tufts University Department of Chemistry Changes to Organic Chemistry and Biochemistry courses effective Fall 2013
Kounaves, Samuel P.
Tufts University Department of Chemistry Changes to Organic Chemistry and Biochemistry courses Professions Advising, the Chemistry Department is pleased to announce changes to the chemistry curriculum in their studies at Tufts. These changes are designed to benefit Chemistry, ACS-Certified Chemistry
Organic Chemistry II Syllabus University of Alaska Fairbanks
Wagner, Diane
, Organic Chemistry I Instructor Thomas Green, Professor of Chemistry Reichardt 174, Phone: 474-1559, Email Course Description This course will focus on the theory of organic chemistry (or chemistry of molecules, and amines. 4. Be able to confidently interpret the IR, Mass, NMR spectra of simple organic compounds
Organic chemistry of coke formation
M Guisnet; P Magnoux
The modes of formation of carbonaceous deposits ("coke") during the transformation of organic compounds over acid and over bifunctional noble metal-acid catalysts are described. At low reaction temperatures, (350°C), the coke components are polyaromatic. Their formation involves hydrogen transfer (acid catalysts) and dehydrogenation (bifunctional catalysts) steps in addition to condensation and rearrangement steps. On microporous catalysts, the retention of coke
Ti (II) Mediated Reactions in Organic Chemistry
Johnson, Jeff S.
Ti (II) Mediated Reactions in Organic Chemistry Chris Tarr University of North Carolina February 23 · Sharpless Asymmetric Epoxidation (TiIV) · Lewis Acid Catalysis (TiIV) · McMurry Coupling (TiIII Ti°) · Tebbe Reagent (TiIV) Crimmins M. T.; King, B. W., Tabet, E. A. J. Am. Chem. Soc. 1997, 119, 7883. McMurry, J. E
Measuring Student Performance in General Organic Chemistry
ERIC Educational Resources Information Center
Austin, Ara C.; Ben-Daat, Hagit; Zhu, Mary; Atkinson, Robert; Barrows, Nathan; Gould, Ian R.
Student performance in general organic chemistry courses is determined by a wide range of factors including cognitive ability, motivation and cultural capital. Previous work on cognitive factors has tended to focus on specific areas rather than exploring performance across all problem types and cognitive skills. In this study, we have categorized…
Safety in the Chemical Laboratory: Experiments Integrating Evaluation of Chemical Hazards into the Chemistry Curriculum.
ERIC Educational Resources Information Center
Pierce, J. T.; And Others
Proposes use of two experiments to sample and analyze contaminents in the laboratory. Experiments focus on estimating hydrogen sulfide levels in the general chemistry laboratory during qualitative analysis and determining the concentration of organic vapors associated with organic chemistry laboratories. (JN)
Purdue University: Division of Organic Chemistry
NSDL National Science Digital Library
Purdue University created this website to promote its organic chemistry department's diverse research initiatives. This expansive website provides links to materials on twelve of the faculty's chemistry research groups. Research includes NMR imaging of micellar solutions, hydride fuel cell examinations, dimerization inhibitors of transcription factors, and gas phase synthesis. Users can find lists of the many publications and view images and photos of the division's work and facilities. Visitors can learn about the many instruments used by the division such as mass spectrometry, continuously rotated cellular reactor, and an ozone generator.
Analytical Chemistry Role Playing Experiments
NSDL National Science Digital Library
This page features a number of laboratory experiments (available for download in PDF format) which allow students the opportunity to role play in groups to solve problems. Experiments involve titrations, gravimetry, atomic absorption, chromatography.
Incorporation of a Cooperative Learning Technique in Organic Chemistry.
ERIC Educational Resources Information Center
Carpenter, Suzanne R.; McMillan, Tim
Describes a student team learning method used in an organic chemistry class at Armstrong Atlantic State University. The Student Teams Achievement Divisions (STAD) method was used in this study. Discusses cooperative learning methods in organic chemistry classes. (KHR)
Our Organic World Pre-AP Chemistry-Project
Our Organic World Pre-AP Chemistry-Project Purpose: To study specific areas of organic chemistry developing the learning book just remember what you liked to do when you were a little kid." 5. Time limit
Synthesis-Spectroscopy Roadmap Problems: Discovering Organic Chemistry
ERIC Educational Resources Information Center
Kurth, Laurie L.; Kurth, Mark J.
Organic chemistry problems that interrelate and integrate synthesis with spectroscopy are presented. These synthesis-spectroscopy roadmap (SSR) problems uniquely engage second-year undergraduate organic chemistry students in the personal discovery of organic chemistry. SSR problems counter the memorize-or-bust strategy that many students tend to…
Cellular uptake: lessons from supramolecular organic chemistry.
Gasparini, Giulio; Bang, Eun-Kyoung; Montenegro, Javier; Matile, Stefan
The objective of this Feature Article is to reflect on the importance of established and emerging principles of supramolecular organic chemistry to address one of the most persistent problems in life sciences. The main topic is dynamic covalent chemistry on cell surfaces, particularly disulfide exchange for thiol-mediated uptake. Examples of boronate and hydrazone exchange are added for contrast, comparison and completion. Of equal importance are the discussions of proximity effects in polyions and counterion hopping, and more recent highlights on ring tension and ion pair-? interactions. These lessons from supramolecular organic chemistry apply to cell-penetrating peptides, particularly the origin of "arginine magic" and the "pyrenebutyrate trick," and the currently emerging complementary "disulfide magic" with cell-penetrating poly(disulfide)s. They further extend to the voltage gating of neuronal potassium channels, gene transfection, and the delivery of siRNA. The collected examples illustrate that the input from conceptually innovative chemistry is essential to address the true challenges in biology beyond incremental progress and random screening. PMID:26030211
Phase Transfer Catalytic Reactions: A Physical Chemistry Laboratory Experiment
NASA Astrophysics Data System (ADS)
Shabestary, Nahid; Khazaeli, Sadegh; Hickman, Richie
This article describes the application of phase-transfer catalysis within an undergraduate physical chemistry laboratory. Phase-transfer catalysis has been covered extensively in various books, articles, and patents. Many important industrial products are manufactured using this technique. However, very little of the subject is reflected in current undergraduate curriculum. The kinetic experiment designed here introduces many important concepts in phase-transfer catalysis and nucleophilic displacement reactions involving both mechanism and kinetics. Since this laboratory exploration includes catalytic reactions, organic synthesis, and chemical analysis, it covers many areas of chemistry. Thus, we believe this can be an important contribution to the students' learning. In this experiment, we have demonstrated that the reactions of alkyl bromides with NaCl under phase-transfer conditions can be carried out replacing bromide with chloride via a nucleophilic displacement reaction within a three-hour physical chemistry laboratory period.
Hydrothermal Synthesis and Characterization of a Metal-Organic Framework by Thermogravimetric Analysis, Powder X-Ray Diffraction, and Infrared Spectroscopy: An Integrative Inorganic Chemistry Experiment
ERIC Educational Resources Information Center
Crane, Johanna L.; Anderson, Kelly E.; Conway, Samantha G.
This advanced undergraduate laboratory experiment involves the synthesis and characterization of a metal-organic framework with microporous channels that are held intact via hydrogen bonding of the coordinated water molecules. The hydrothermal synthesis of Co[subscript 3](BTC)[subscript 2]·12H[subscript 2]O (BTC = 1,3,5-benzene tricarboxylic acid)…
An Experiment in Forensic Chemistry: The Breathalyzer.
ERIC Educational Resources Information Center
Timmer, William C.
Describes a simple experiment done in a quantitative analysis course that illustrates the chemistry of the breath alcohol test. Discusses the development and use of the Breathalyzer. Outlines the experimental procedure, along with the appropriate calculations and discussion of the results. (TW)
A Pre-Vacation Chemistry Experiment
ERIC Educational Resources Information Center
Gabel, Dorothy; McSweeny, Jean
Describes a chemistry experiment appropriate for the day before Christmas vacation. Students prepare candy canes by following a recipe written in chemical terms. This illustrates that food is composed of chemicals and that the processes involved in cooking are chemical and physical changes. (JR)
Making Sense of the Arrow-Pushing Formalism among Chemistry Majors Enrolled in Organic Chemistry
ERIC Educational Resources Information Center
Ferguson, Robert; Bodner, George M.
This paper reports results of a qualitative study of sixteen students enrolled in a second year organic chemistry course for chemistry and chemical engineering majors. The focus of the study was student use of the arrow-pushing formalism that plays a central role in both the teaching and practice of organic chemistry. The goal of the study was to…
Contextualized Chemistry Education: The American experience
NASA Astrophysics Data System (ADS)
Schwartz, A. Truman
This paper is a survey of context-based chemistry education in the United States. It begins with a very brief overview of twentieth-century chemistry texts and teaching methods, followed by a short description of a pioneering secondary school text. The major emphasis is on post-secondary instruction and the central case study is provided by Chemistry in Context, a university text intended for students who are not specializing in science. The paper is more concerned with strategies for curriculum reform than with educational research, and the emphasis is more pragmatic than theoretical. A chronological sequence is used to trace the creation of Chemistry in Context. This developmental account is overlaid with the curricular representations of Goodlad and Van den Akker. The Ideal Curriculum was the goal, but the Formal Curriculum was created and revised as a consequence of iteration involving perceptions of the users, the implementation of the curriculum, the experience of students and teachers, and formal and informal assessment of what was attained. The paper also includes descriptions of other, more recent, context-based college chemistry curricula. It concludes with a list of problems and unanswered questions relating to this pedagogical approach.
On the nature of interstellar organic chemistry
NASA Astrophysics Data System (ADS)
Charnley, Steven B.
A theory for the origin of all organic molecules observed in regions of massive and low-mass star formation, as well as in dark molecular clouds is described. On dust grains, single atom addition reactions and stability of the intermediate radicals, mechanisms similar to those believed to form the organic component of the Murchison meteorite, lead to a very limited number of mantle compositions depending upon the degree of hydrogenation. The key step in the theory is the formation of the formyl radical by H atom addition (by quantum tunnelling) to CO. Subsequent H atom additions lead to formaldehyde and methanol, as previously suggested; C, N, and O atoms can also undergo additions to HCO. For increasing hydrogenation, the mantle types include one in which there is little contribution from formyl-initiated chemistry; one in which an acetylenic chain develops through C atom additions; and others where the acetylenic chain is increasingly hydrogenated to form aldehydes and alcohols. Following evaporation of grain mantles, such as occurs in protostellar hot cores, these molecules can form new organics, for example, by alkyl cation transfer from alcohols. In dark clouds, different mantles lead to different gas phase organics. This scenario accounts naturally for the formation of many interstellar organics for which none presently exists, predicts observable correlations between specific interstellar molecules, indicates the presence of many new organic molecules and why several others are not observed.
Organic chemistry in the oceans of Titan
NASA Astrophysics Data System (ADS)
Raulin, F.
On Titan, most of the organics present in the atmosphere must condense in the lower stratosphere and be solid near the surface, except methane, ethane, propane, propene and 1-butene which must be liquid and could form oceans containing large fractions of dissolved N2. Chemical evolution on Titan must have followed a way very different from the terrestrial one, involving physical chemical processes in a cryogenic apolar solvent mainly composed of CH4-C2H6-N2, in place of organic chemistry in water. Systematic study of the volumic mass and solubility of organics in such a cryogenic mixture of various compositions, at 94K, is presented, using thermodynamic modelling. The results suggest that the oceans of Titan could be free of any "icebergs" of organic compounds. These oceans could be very rich in dissolved organics, with relatively high concentrations, in the range 1 - 10-6M. In addition, the concentration of several of the organic solutes should be constant, buffered by a bottom layer of the corresponding compound in the solid phase.
Shock-induced chemistry in organic materials
Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Steve [Los Alamos National Laboratory; Engelke, Ray [Los Alamos National Laboratory; Manner, Virginia [Los Alamos National Laboratory; Chellappa, Raja [Los Alamos National Laboratory; Yoo, Choong - Shik [WASHINGTON STATE UNIV
The combined 'extreme' environments of high pressure, temperature, and strain rates, encountered under shock loading, offer enormous potential for the discovery of new paradigms in chemical reactivity not possible under more benign conditions. All organic materials are expected to react under these conditions, yet we currently understand very little about the first bond-breaking steps behind the shock front, such as in the shock initiation of explosives, or shock-induced reactivity of other relevant materials. Here, I will present recent experimental results of shock-induced chemistry in a variety of organic materials under sustained shock conditions. A comparison between the reactivity of different structures is given, and a perspective on the kinetics of reaction completion under shock drives.
Simple Organic Chemistry in the Horsehead Nebula
NASA Astrophysics Data System (ADS)
Goicoechea, J. R.; Pety, J.; Gerin, M.; Hily-Blant, P.; Teyssier, D.; Roueff, E.
We present our latest results on carbon chemistry in the Horsehead nebula, one of the most famous objects in the sky and a unique laboratory to understand the chemistry of interstellar clouds} illuminated by UV radiation} from nearby stars. Photodissociation regions (PDRs) are interesting intermediate media between diffuse and dense dark clouds, thus enabling astrochemists to probe a large variety of physical and chemical processes. In particular, our high resolution astronomical observations show that the Horsehead edge is a realistic template to determine the molecular inventory in PDRs and to investigate the photostability of simple organic molecules}. In this contribution we show that simple carbon chains and rings (CCH, c-C3H2 and C4H) are tightly spatially correlated with each other and with the emission of polycyclic aromatic hydrocarbons (PAHs). We show how molecules such as HCO+ start to be enriched in deuterium (DCO+/HCO+ > 0.02) as the gas cools down in the densest and UV protected prestellar condensations. We also determine the gas phase sulfur abundance in the UV irradiated gas from CS and HCS+ observations and chemical modeling. We finally present the first results of our search of gas phase species with a probable dust grain surface origin (e.g., H2S). We stress the need of well conceived astronomical observations together with models that treat consistently both the photochemistry of simple organic species and the radiative transport of their emission lines.
Glyoxal induced atmospheric photosensitized chemistry leading to organic aerosol growth.
Rossignol, Stéphanie; Aregahegn, Kifle Z; Tinel, Liselotte; Fine, Ludovic; Nozičre, Barbara; George, Christian
In recent years, it has been proposed that gas phase glyoxal could significantly contribute to ambient organic aerosol (OA) mass through multiphase chemistry. Of particular interest is the reaction between glyoxal and ammonium cations producing light-absorbing compounds such as imidazole derivatives. It was recently shown that imidazole-2-carboxaldehyde (IC) can act as a photosensitizer, initiating aerosol growth in the presence of gaseous volatile organic compounds. Given the potential importance of this new photosensitized growth pathway for ambient OA, the related reaction mechanism was investigated at a molecular level. Bulk and flow tube experiments were performed to identify major products of the reaction of limonene with the triplet state of IC by direct (±)ESI-HRMS and UPLC/(±)HESI-HRMS analysis. Detection of recombination products of IC with limonene or with itself, in bulk and flow tube experiments, showed that IC is able to initiate a radical chemistry in the aerosol phase under realistic irradiation conditions. Furthermore, highly oxygenated limonene reaction products were detected, clearly explaining the observed OA growth. The chemistry of peroxy radicals derived from limonene upon addition of oxygen explains the formation of such low-volatile compounds without any traditional gas phase oxidant. PMID:24555477
Problem Types in Synthetic Organic Chemistry Research: Implications for the Development of Curricular Problems for Second-Year Level Organic Chemistry Instruction
ERIC Educational Resources Information Center
Raker, Jeffrey R.; Towns, Marcy H.
Understanding of the nature of science is key to the development of new curricular materials that mirror the practice of science. Three problem types (project level, synthetic planning, and day-to-day) in synthetic organic chemistry emerged during a thematic content analysis of the research experiences of eight practising synthetic organic…
QM/MM investigations of organic chemistry oriented questions.
Schmidt, Thomas C; Paasche, Alexander; Grebner, Christoph; Ansorg, Kay; Becker, Johannes; Lee, Wook; Engels, Bernd
About 35 years after its first suggestion, QM/MM became the standard theoretical approach to investigate enzymatic structures and processes. The success is due to the ability of QM/MM to provide an accurate atomistic picture of enzymes and related processes. This picture can even be turned into a movie if nuclei-dynamics is taken into account to describe enzymatic processes. In the field of organic chemistry, QM/MM methods are used to a much lesser extent although almost all relevant processes happen in condensed matter or are influenced by complicated interactions between substrate and catalyst. There is less importance for theoretical organic chemistry since the influence of nonpolar solvents is rather weak and the effect of polar solvents can often be accurately described by continuum approaches. Catalytic processes (homogeneous and heterogeneous) can often be reduced to truncated model systems, which are so small that pure quantum-mechanical approaches can be employed. However, since QM/MM becomes more and more efficient due to the success in software and hardware developments, it is more and more used in theoretical organic chemistry to study effects which result from the molecular nature of the environment. It is shown by many examples discussed in this review that the influence can be tremendous, even for nonpolar reactions. The importance of environmental effects in theoretical spectroscopy was already known. Due to its benefits, QM/MM can be expected to experience ongoing growth for the next decade.In the present chapter we give an overview of QM/MM developments and their importance in theoretical organic chemistry, and review applications which give impressions of the possibilities and the importance of the relevant effects. Since there is already a bunch of excellent reviews dealing with QM/MM, we will discuss fundamental ingredients and developments of QM/MM very briefly with a focus on very recent progress. For the applications we follow a similar strategy. PMID:22392477
Atmospheric Prebiotic Chemistry and Organic Hazes
Trainer, Melissa G.
Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of prebiotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer – if formed – would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere. PMID:24143126
Fun with Photons, Reactive Intermediates, and Friends. Skating on the Edge of the Paradigms of Physical Organic Chemistry, Organic
Turro, Nicholas J.
of Physical Organic Chemistry, Organic Supramolecular Photochemistry, and Spin Chemistry Nicholas J. Turro of the crucial role of geometry and structure in the rapid development of organic chemistry and physical organic chemistry over the past century. 1. PHYSICAL ORGANIC CHEMISTRY AND PHOTOCHEMISTRY: REACTIVE INTERMEDIATES
Distributed Pore Chemistry in Porous Organic Polymers
NASA Technical Reports Server (NTRS)
Koontz, Steven L. (Inventor)
A method for making a biocompatible polymer article using a uniform atomic oxygen treatment is disclosed. The sub-strate may be subsequently optionally grated with a compatibilizing compound. Compatibilizing compounds may include proteins, phosphorylcholine groups, platelet adhesion preventing polymers, albumin adhesion promoters, and the like. The compatibilized substrate may also have a living cell layer adhered thereto. The atomic oxygen is preferably produced by a flowing afterglow microwave discharge, wherein the substrate resides in a sidearm out of the plasma. Also, methods for culturing cells for various purposes using the various membranes are disclosed as well. Also disclosed are porous organic polymers having a distributed pore chemistry (DPC) comprising hydrophilic and hydrophobic region, and a method for making the DPC by exposing the polymer to atomic oxygen wherein the rate of hydrophilization is greater than the rate of mass loss.
Mass spectrometry. [in organic ion and biorganic chemistry and medicine
NASA Technical Reports Server (NTRS)
Burlingame, A. L.; Cox, R. E.; Derrick, P. J.
Review of the present status of mass spectrometry in the light of pertinent recent publications spanning the period from December 1971 to January 1974. Following an initial survey of techniques, instruments, and computer applications, a sharp distinction is made between the chemistry of organic (radical-)ions and analytical applications in biorganic chemistry and medicine. The emphasis is on the chemistry of organic (radical-)ions at the expense of inorganic, organometallic, and surface ion chemistry. Biochemistry and medicine are chosen because of their contemporary importance and because of the stupendous contributions of mass spectroscopy to these fields in the past two years. In the review of gas-phase organic ion chemistry, special attention is given to studies making significant contributions to the understanding of ion chemistry.
Interstellar grain chemistry and organic molecules
NASA Technical Reports Server (NTRS)
Allamandola, L. J.; Sandford, S. A.
The detection of prominant infrared absorption bands at 3250, 2170, 2138, 1670 and 1470 cm(-1) (3.08, 4.61, 4.677, 5.99 and 6.80 micron m) associated with molecular clouds show that mixed molecular (icy) grain mantles are an important component of the interstellar dust in the dense interstellar medium. These ices, which contain many organic molecules, may also be the production site of the more complex organic grain mantles detected in the diffuse interstellar medium. Theoretical calculations employing gas phase as well as grain surface reactions predict that the ices should be dominated only by the simple molecules H2O, H2CO, N2, CO, O2, NH3, CH4, possibly CH3OH, and their deuterated counterparts. However, spectroscopic observations in the 2500 to 1250 cm(-1)(4 to 8 micron m) range show substantial variation from source reactions alone. By comparing these astronomical spectra with the spectra of laboratory-produced analogs of interstellar ices, one can determine the composition and abundance of the materials frozen on the grains in dense clouds. Experiments are described in which the chemical evolution of an interstellar ice analog is determined during irradiation and subsequent warm-up. Particular attention is paid to the types of moderately complex organic materials produced during these experiments which are likely to be present in interstellar grains and cometary ices.
Promoting Chemistry Learning through Undergraduate Work Experience in the Chemistry Lab: A Practical Approach
ERIC Educational Resources Information Center
Yu, Hong-Bin
Hiring undergraduate lab assistants in chemistry departments is common in college. However, few studies have focused on promoting undergraduate chemistry learning and thinking skills through this work experience in chemistry teaching laboratories. This article discusses the strategy we implemented in the lab assistant program. The…
Visual Experiments Supporting Four Basic Concepts in Chemistry
François Saint-Antonin
Visual experiments based on color mixing are proposed to illustrate four basic concepts in chemistry. These visual experiments involve connecting liquid puddles of different colors placed on a flat glass surface and observing and describing the phenomena that occur. Employing as nonspecialized a vocabulary as possible, these experiments can be used as part of a general introduction to chemistry.
Photolysis of 4-Phenyl-1,3-dioxolan-2-one: An Undergraduate Experiment in Free Radical Chemistry.
ERIC Educational Resources Information Center
White, Rick C.; Ma, Sha
Describes a photochemistry experiment designed to introduce photochemical techniques and experience free radical chemistry. Selects Nuclear Magnetic Resonance spectroscopy for the analysis. This activity is suggested for use in an upper level undergraduate organic course. (MVL)
A One-Pot, Asymmetric Robinson Annulation in the Organic Chemistry Majors Laboratory
ERIC Educational Resources Information Center
Lazarski, Kiel E.; Rich, Alan A.; Mascarenhas, Cheryl M.
The Robinson annulation is a topic of importance in the second-year organic curriculum. A one-pot, enantioselective Robinson annulation is described. The experiment is completed in two lab periods and is geared towards the second-year organic chemistry major. To our knowledge, this is the first example of a one-pot enantioselective Robinson…
An Undergraduate Organic Chemistry Laboratory: The Facile Hydrogenation of Methyl Trans-Cinnamate
ERIC Educational Resources Information Center
O'Connor, Kenneth J.; Zuspan, Kimberly; Berry, Lonnie
Hydrogenation of alkenes is an important reaction in the synthesis of organic molecules. In this experiment, students conduct a high-yield microscale hydrogenation reaction of methyl "trans"-cinnamate using a readily available, safe, and convenient hydrogen source. The conditions are similar to those seen in an organic chemistry textbook for an…
Spicing Things up by Adding Color and Relieving Pain: The Use of "Napoleon's Buttons" in Organic Chemistry
ERIC Educational Resources Information Center
Bucholtz, Kevin M.
For some students, organic chemistry can be a distant subject and unrelated to any courses they have seen in their college careers. To develop a more contextual learning experience in organic chemistry, an additional text, "Napoleon's Buttons: 17 Molecules That Changed History," by Penny Le Couteur and Jay Burreson, was incorporated as a…
Simple Organic Chemistry in the Horsehead Nebula
J. R. Goicoechea; J. Pety; M. Gerin; P. Hily-Blant; D. Teyssier; E. Roueff
We present our latest results on carbon chemistry in the Horsehead nebula, one of the most famous objects in the sky and a unique laboratory to understand the chemistry of interstellar clouds} illuminated by UV radiation} from nearby stars. Photodissociation regions (PDRs) are interesting intermediate media between diffuse and dense dark clouds, thus enabling astrochemists to probe a large variety
Greener Approaches to Undergraduate Chemistry Experiments.
ERIC Educational Resources Information Center
Kirchhoff, Mary, Ed.; Ryan, Mary Ann, Ed.
This laboratory manual introduces the idea of Green Chemistry, which is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. Instructional samples are included to help teachers integrate green chemistry into the college chemistry curriculum. Each laboratory includes: (1) a…
A Template-Controlled Solid-State Reaction for the Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Friscic, Tomislav; Hamilton, Tamara D.; Papaefstathiou, Giannis S.; MacGillivray, Leonard R.
An experiment for the organic chemistry laboratory that involves a template-controlled solid-state reaction is described. The experiment utilizes a template to direct the assembly of an olefin in the solid state that undergoes a [2 + 2] photodimerization.
Teaching Organic Chemistry by a Modified Keller Plan
ERIC Educational Resources Information Center
Emerson, David W.
Describes an organic chemistry course designed as a modification of the Keller plan; lists the basic assumptions of the course design; outlines how the course was conducted; and compares the grade distribution to that of a traditional class. (GS)
Organic chemistry textbooks generally treat geminal diols as curiosities-exceptions to the stability of the C=O double bond. However, most aldehydes of environmental significance, to wit, trichloroethanal (chloral), methanala (formaldehyde), ethanal (acetaldehyde), and propanal ...
A Perspective on Physical Organic Chemistry
A perspective on the development of mechanistic carbene chemistry is presented. The author will point out questions that have been answered, and a next generation of questions will be proposed. PMID:24571434
Approaches to High Throughput Physical Organic Chemistry
Portal, Christophe
Over the past ten years, the development of High Throughput (HT) synthetic chemistry techniques has allowed the rapid preparation of libraries of hundreds to thousands of compounds. These tools are now extensively used for drug and material...
What Do I Remember? The Role of Lecture-Experiments in Teaching Chemistry.
ERIC Educational Resources Information Center
Bent, Henry A.; Bent, Henry E.
Described are different chemistry curricula that use lecture-experiments. Different components are discussed within the lecture-experiment format, such as determinism, memory, note taking, descriptive chemistry, and holistic chemistry. Also discussed are different personalities in chemistry education. (DS)
Automated Combinatorial Chemistry in the Organic Chemistry Majors Laboratory
ERIC Educational Resources Information Center
Nichols, Christopher J.; Hanne, Larry F.
A multidisciplinary experiment has been developed in which students each synthesize a combinatorial library of 48 hydrazones with the aid of a liquid-handling robot. Each product is then subjected to a Kirby-Bauer disk diffusion assay to assess its antibacterial activity. Students gain experience working with automation and at the…
Academia–Industry Symbiosis in Organic Chemistry
Conspectus Collaboration between academia and industry is a growing phenomenon within the chemistry community. These sectors have long held strong ties since academia traditionally trains the future scientists of the corporate world, but the recent drastic decrease of public funding is motivating the academic world to seek more private grants. This concept of industrial "sponsoring" is not new, and in the past, some companies granted substantial amounts of money per annum to various academic institutions in exchange for prime access to all their scientific discoveries and inventions. However, academic and industrial interests were not always aligned, and therefore the investment has become increasingly difficult to justify from industry's point of view. With fluctuating macroeconomic factors, this type of unrestricted grant has become more rare and has been largely replaced by smaller and more focused partnerships. In our view, forging a partnership with industry can be a golden opportunity for both parties and can represent a true symbiosis. This type of project-specific collaboration is engendered by industry's desire to access very specific academic expertise that is required for the development of new technologies at the forefront of science. Since financial pressures do not allow companies to spend the time to acquire this expertise and even less to explore fundamental research, partnering with an academic laboratory whose research is related to the problem gives them a viable alternative. From an academic standpoint, it represents the perfect occasion to apply "pure science" research concepts to solve problems that benefit humanity. Moreover, it offers a unique opportunity for students to face challenges from the "real world" at an early stage of their career. Although not every problem in industry can be solved by research developments in academia, we argue that there is significant scientific overlap between these two seemingly disparate groups, thereby presenting an opportunity for a symbiosis. This type of partnership is challenging but can be a win–win situation if both parties agree on some general guidelines, including clearly defined goals and deliverables, biweekly meetings to track research progress, and quarterly or annual meetings to recognize overarching, common objectives. This Account summarizes our personal experience concerning collaborations with various industrial groups and the way it impacted the research programs for both sides in a symbiotic fashion. PMID:25702529
An investigation of student understanding in the undergraduate organic chemistry laboratory
NASA Astrophysics Data System (ADS)
Grutsch, John Leo, Jr.
Laboratory activities in organic chemistry involve a mixture of sophisticated logic and empirical observation that requires the integration of mechanistic thought, laboratory technique, and problem-solving skills. In an effort to understand how students develop the thought processes and problem-solving skills necessary for laboratory work in organic chemistry, student understanding of how the interaction between a reaction system (reactants or starting material(s), reagent(s), and/or solvent), experimental variables (pH, temperature, concentrations, etc), provides a result of interest (yield, selectivity, purity, etc.) for an experiment performed in the organic chemistry laboratory was investigated through the collection of responses to questions posed on pre-laboratory quizzes followed by in-depth interviews during which student volunteers discussed their responses along with their experiences in the laboratory. The conceptual change theory of learning which assumes new conceptions are understood, judged, acquired, or rejected in a conceptual context was used as a theoretical paradigm to examine students responses to questions posed on pre-laboratory quizzes and transcripts of the interviews with student volunteers. Students were found to not have developed a mechanistic understanding of how the interaction between a reaction system (reactants or starting material(s), reagent(s), and/or solvent), experimental variables (pH, temperature, concentrations, etc), provides a result of interest (yield, selectivity, purity, etc.) for an experiment performed in the organic chemistry laboratory. However, students' prior exposure to and understanding of chemical concepts was found to simultaneously assist and hinder in their development of a partial mechanistic understanding of how a reaction system (reactants or starting material(s), reagent(s), and/or solvent), experimental variables (pH, temperature, concentrations, etc), interact to provide a result of interest (yield, selectivity, purity, etc.). Even though students were able to develop a partial mechanistic understanding, they still did not understand the rationale behind chemical or physical manipulation performed in the organic chemistry laboratory or how either may be applied to other experiments. Therefore, experiments performed in the organic chemistry laboratory became activities in which students gave little thought to what they were doing resulting in little meaningful learning, unsafe practices, and an unpleasant experience that demotivated students. To address this deficiency, instructors need to create an environment where students are allowed to develop an understanding of the role of reagents and reaction conditions in an experiment in order to acquire the knowledge and skills that permits them to develop a deep mechanistic understanding of how organic chemistry reactions are implemented in the organic chemistry laboratory.
Chemistry on dust grains: the laboratory experiments
NASA Astrophysics Data System (ADS)
Pirronello, V.; Manico, G.; Roser, J.; Vidali, G.
Some of the most important molecular species observed in interstellar clouds are not formed efficiently enough by reactions occurring in the gas phase and therefore dust grains may play the fundamental role of catalysts. In this talk I will report on experiments performed recently on surfaces and in conditions close to those encountered in the ISM to obtain the production rate of molecular hydrogen and carbon dioxide and to deduce hints on the mechanisms that may be responsible for their formation. The choice to concentrate our attention on these species has been dictated by their unquestionable relevance. H2 is undoubtedly the most important molecule in space: it is in fact by several orders of magnitude the most abundant; it actively enters in all gas phase reaction schemes that produce other chemical species and it provides efficient cooling to clouds that, reducing their energy budget, facilitates their gravitational collapse and hence the formation of stars. CO2 is observed in a wide variety of interstellar regions, in warm proto-stellar objects and also in dense quiescent clouds, but almost exclusively in the solid phase, it therefore may be considered a good probe of surface chemistry. I will also briefly describe some of the modeling performed by us and of the astrophysical consequences that can be deduced.
Contextualized Chemistry Education: The American Experience
ERIC Educational Resources Information Center
Schwartz, A. Truman
This paper is a survey of context-based chemistry education in the United States. It begins with a very brief overview of twentieth-century chemistry texts and teaching methods, followed by a short description of a pioneering secondary school text. The major emphasis is on post-secondary instruction and the central case study is provided by…
Using Popular Nonfiction in Organic Chemistry: Teaching More than Content
ERIC Educational Resources Information Center
Amaral, Katie E.; Shibley, Ivan A., Jr.
Assigning a popular nonfiction book as a supplemental text in organic chemistry can help students learn valuable skills. An analysis of student feedback on assignments related to a nonfiction book in two different organic courses revealed that students applied the information from the book, improved their communication skills, and were more…
Organic chemistry and biology of the interstellar medium
NASA Technical Reports Server (NTRS)
Sagan, C.
Interstellar organic chemistry is discussed as the field of study emerging from the discovery of microwave lines of formaldehyde and of hydrogen cyanide in the interstellar medium. The reliability of molecular identifications and comparisons of interstellar and cometary compounds are considered, along with the degradational origin of simple organics. It is pointed out that the contribution of interstellar organic chemistry to problems in biology is not substantive but analogical. The interstellar medium reveals the operation of chemical processes which, on earth and perhaps on vast numbers of planets throughout the universe, led to the origin of life, but the actual molecules of the interstellar medium are unlikely to play any significant biological role.
Synthesis Road Map Problems in Organic Chemistry
ERIC Educational Resources Information Center
Schaller, Chris P.; Graham, Kate J.; Jones, T. Nicholas
Road map problems ask students to integrate their knowledge of organic reactions with pattern recognition skills to "fill in the blanks" in the synthesis of an organic compound. Students are asked to identify familiar organic reactions in unfamiliar contexts. A practical context, such as a medicinally useful target compound, helps…
Computational Organic Chemistry: The "Can" and "Can't" be Done with Non Supercomputers in Aromatic Chemistry.
Adler, Joan
Quantum Chemistry, Technion Israel Institute of Technology, Haifa 32000, Israel Fax: (+) 972Computational Organic Chemistry: The "Can" and "Can't" be Done with Non Supercomputers in Aromatic Chemistry. Amnon Stanger Schulich faculty of Chemistry and The Lise-Meitner-Minerva Center for Computational
Synthesis of Ethyl Nalidixate: A Medicinal Chemistry Experiment
ERIC Educational Resources Information Center
Leslie, Ray; Leeb, Elaine; Smith, Robert B.
A series of laboratory experiments that complement a medicinal chemistry lecture course in drug design and development have been developed. The synthesis of ethyl nalidixate covers three separate experimental procedures, all of which can be completed in three, standard three-hour lab classes and incorporate aspects of green chemistry such as…
Structure Determination of Unknown Organic Liquids Using NMR and IR Spectroscopy: A General Chemistry Laboratory
ERIC Educational Resources Information Center
Pavel, John T.; Hyde, Erin C.; Bruch, Martha D.
This experiment introduced general chemistry students to the basic concepts of organic structures and to the power of spectroscopic methods for structure determination. Students employed a combination of IR and NMR spectroscopy to perform de novo structure determination of unknown alcohols, without being provided with a list of possible…
Green Oxidation of Menthol Enantiomers and Analysis by Circular Dichroism Spectroscopy: An Advanced Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Geiger, H. Cristina; Donohoe, James S.
Green chemistry addresses environmental concerns associated with chemical processes and increases awareness of possible harmful effects of chemical reagents. Efficient reactions that eliminate or reduce the use of organic solvents or toxic reagents are increasingly available. A two-week experiment is reported that entails the calcium hypochlorite…
A Guided Inquiry Liquid/Liquid Extractions Laboratory for Introductory Organic Chemistry
ERIC Educational Resources Information Center
Raydo, Margaret L.; Church, Megan S.; Taylor, Zane W.; Taylor, Christopher E.; Danowitz, Amy M.
A guided inquiry laboratory experiment for teaching liquid/liquid extractions to first semester undergraduate organic chemistry students is described. This laboratory is particularly useful for introductory students as the analytes that are separated are highly colored dye molecules. This allows students to track into which phase each analyte…
Interdisciplinary Learning for Chemical Engineering Students from Organic Chemistry Synthesis Lab to Reactor Design to Separation
ERIC Educational Resources Information Center
Armstrong, Matt; Comitz, Richard L.; Biaglow, Andrew; Lachance, Russ; Sloop, Joseph
A novel approach to the Chemical Engineering curriculum sequence of courses at West Point enabled our students to experience a much more realistic design process, which more closely replicated a real world scenario. Students conduct the synthesis in the organic chemistry lab, then conduct computer modeling of the reaction with ChemCad and…
Organic Chemistry Educators' Perspectives on Fundamental Concepts and Misconceptions: An Exploratory Study
ERIC Educational Resources Information Center
Duis, Jennifer M.
An exploratory study was conducted with 23 organic chemistry educators to discover what general chemistry concepts they typically review, the concepts they believe are fundamental to introductory organic chemistry, the topics students find most difficult in the subject, and the misconceptions they observe in undergraduate organic chemistry…
Predicted versus Actual Performance in Undergraduate Organic Chemistry and Implications for Student Advising
ERIC Educational Resources Information Center
Pursell, David P.
Performance as measured by grades in the first and second semesters of organic chemistry was predicted using pre-college measures (SAT scores, high school rank, validation exams) and college measures (general chemistry GPA, overall college GPA prior to beginning organic chemistry, first-semester organic chemistry GPA). Data indicate that overall…
Incorporating a Substantial Writing Assignment into Organic Chemistry: Library Research, Peer Review, and Assessment
Ivan A. Shibley Jr.; Louis K. Milakofsky; Cynthia L. Nicotera
A substantial writing assignment in an organic chemistry course provides a means of allowing students to direct their own learning about a specific application of organic chemistry. The use of peer review provided additional benefits: students learned organic chemistry from reading each others' papers and learned more about how classmates write about chemistry. Recommendations about how best to collaborate with
Chemistry under Your Skin? Experiments with Tattoo Inks for Secondary School Chemistry Students
ERIC Educational Resources Information Center
Stuckey, Marc; Eilks, Ingo
This paper discusses a set of easy, hands-on experiments that inquire into and differentiate among tattoo inks of varying quality. A classroom scenario is described for integrating these experiments into secondary school chemistry classes. Initial experiences from the classroom are also presented.
Atmospheric chemistry's enhanced effect on organic aerosols
NSDL National Science Digital Library
Molina et al.
Results of this study indicate that chemical processes in the atmosphere may remove nearly as much organic carbon from the troposphere as rain, which was previously considered the major mechanism for eliminating the pollutant particles. Details are discussed in article.
The physics and (radio)chemistry of solar neutrino experiments
R. L. Hahn
The situation in solar neutrino science has changed drastically in the past several years, with results now available from four neutrino experiments that use different methods to look at different regions of the solar-neutrino energy-spectrum. While the goal of all of these experiments is physics, they all rely heavily on chemistry and radiochemistry. Three of these experiments are radiochemical; the
Hydrogen chemistry - Perspective on experiment and theory
F. Kaufman
A review is presented of the advantages and limitations of various experimental methods for the investigation of the kinetics of hydrogen chemistry, including classic thermal and photochemical methods and the crossed molecular beam method. Special attention is given to the flash photolysis-resonance fluorescence apparatus developed by Braun et al, in which repetitive vacuum UV flashes result in the photolytic generation
Remote-controlled experiments with cloud chemistry
NASA Astrophysics Data System (ADS)
Skilton, Ryan A.; Bourne, Richard A.; Amara, Zacharias; Horvath, Raphael; Jin, Jing; Scully, Michael J.; Streng, Emilia; Tang, Samantha L. Y.; Summers, Peter A.; Wang, Jiawei; Pérez, Eduardo; Asfaw, Nigist; Aydos, Guilherme L. P.; Dupont, Jairton; Comak, Gurbuz; George, Michael W.; Poliakoff, Martyn
Developing cleaner chemical processes often involves sophisticated flow-chemistry equipment that is not available in many economically developing countries. For reactions where it is the data that are important rather than the physical product, the networking of chemists across the internet to allow remote experimentation offers a viable solution to this problem.
The Organic Chemistry of Conducting Polymers
Tolbert, Laren Malcolm [Georgia Institute of Technology
For the last several years, we have examined the fundamental principles of conduction in one-dimensional systems, i.e., molecular "wires". It is, of course, widely recognized that such systems, as components of electronically conductive materials, function in a two- and three-dimensional milieu. Thus interchain hopping and grain-boundary resistivity are limiting conductivity factors in highly conductive materials, and overall conductivity is a function of through-chain and boundary hopping. We have given considerable attention to the basic principles underlying charge transport (the "rules of the game") in two-dimensional systems by using model systems which allow direct observation of such processes, including the examination of tunneling and hopping as components of charge transfer. In related work, we have spent considerable effort on the chemistry of conjugated heteropolymers, most especially polythiophens, with the aim of using these most efficient of readily available electroactive polymers in photovoltaic devices.
Solventless and One-Pot Synthesis of Cu(II) Phthalocyanine Complex: A Green Chemistry Experiment
ERIC Educational Resources Information Center
Sharma, R. K.; Sharma, Chetna; Sidhwani, Indu Tucker
With the growing awareness of green chemistry, it is increasingly important for students to understand this concept in the context of laboratory experiments. Although microwave-assisted organic synthesis has become a common and invaluable technique in recent years, there have been few procedures published for microwave-assisted inorganic synthesis…
CHEMISTRY 324W Fall 2010 ORGANIC LABORATORY
Wagner, Diane
of practical data, techniques, and references by A.J. Gordon and Richard A. Ford (John Wiley & Sons is an good up data and text files Fees: (1) Material fee for chemicals, glassware breakage, and other supplies of organic laboratory practices. These include: 1) Synthetic procedures 2) Chromatographic analysis (gc, tlc
Toward Consistent Terminology for Cyclohexane Conformers in Introductory Organic Chemistry
ERIC Educational Resources Information Center
Nelson, Donna J.; Brammer, Christopher N.
Recommended changes in use of cyclohexane conformers and their nomenclature will remedy inconsistencies in cyclohexane conformers and their nomenclature that exist across currently used organic chemistry textbooks. These inconsistencies prompted this logical analysis and the resulting recommendations. Recommended conformer names are "chair",…
The Role of Spatial Ability and Achievement in Organic Chemistry.
ERIC Educational Resources Information Center
Pribyl, Jeffrey R.; Bodner, George M.
This study investigated the role that spatial ability has in achievement in organic chemistry. Spatial ability was defined as containing two subfactors--spatial visualization and spatial orientation. Spatial visualization is the ability to mentally manipulate pictorially presented stimuli; involved in the processes of manipulation are the…
Telling It like It Is: Teaching Mechanisms in Organic Chemistry
ERIC Educational Resources Information Center
Ault, Addison
In this article I support and extend the ideas presented by J. Brent Friesen in his article "Saying What You Mean; Teaching Mechanisms in Organic Chemistry" ("JCE" November, 2008). I emphasize "telling the truth" about proton transfers. The truth is that in aqueous acid most reactions are subject to "specific" acid catalysis: the only kinetically…
Integrating Symmetry in Stereochemical Analysis in Introductory Organic Chemistry
ERIC Educational Resources Information Center
Taagepera, Mare; Arasasingham, Ramesh D.; King, Susan; Potter, Frank; Martorell, Ingrid; Ford, David; Wu, Jason; Kearney, Aaron M.
We report a comparative study using "knowledge space theory" (KAT) to assess the impact of a hands-on laboratory exercise that used molecular model kits to emphasize the connections between a plane of symmetry, Charity, and isomerism in an introductory organic chemistry course. The experimental design compared three groups of students--two that…
Implementing a Student-Designed Green Chemistry Laboratory Project in Organic Chemistry
ERIC Educational Resources Information Center
Graham, Kate J.; Jones, T. Nicholas; Schaller, Chris P.; McIntee, Edward J.
A multiweek organic chemistry laboratory project is described that emphasizes sustainable practices in experimental design. An emphasis on student-driven development of the project is meant to mirror the independent nature of research. Students propose environmentally friendly modifications of several reactions. With instructor feedback, students…
Student Response to a Partial Inversion of an Organic Chemistry Course for Non-Chemistry Majors
ERIC Educational Resources Information Center
Rein, Kathleen S.; Brookes, David T.
We report the student response to a two-year transformation of a one-semester organic chemistry course for nonchemistry majors. The transformed course adopted a peer led team learning approach and incorporated case studies. Student attitudes toward the course transformation were assessed throughout the semester, and adjustments to the methods were…
NSDL National Science Digital Library
Allan A. Gahr
Concept mapping in the organic chemistry laboratory can supplant cookbook activities with higher cognitive exercises. The common thread of most organic lab experiments is the synthesis, isolation, purification, and characterization of a carbon compound. T
ERIC Educational Resources Information Center
School Science Review, 1981
Describes 13 activities, experiments and demonstrations, including the preparation of iron (III) chloride, simple alpha-helix model, investigating camping gas, redox reactions of some organic compounds, a liquid crystal thermometer, and the oxidation number concept in organic chemistry. (JN)
Advanced Undergraduate Experiments in Thermoanalytical Chemistry.
ERIC Educational Resources Information Center
Hill, J. O.; Magee, R. J.
Describes several experiments using the techniques of thermal analysis and thermometric titrimetry. Defines thermal analysis and several recent branches of the technique. Notes most of the experiments use simple equipment and standard laboratory techniques. (MVL)
Two Multipurpose Thermochemical Experiments for General Chemistry.
ERIC Educational Resources Information Center
Wentworth, R. A. D.
Describes two experiments designed to provide concepts on the difference between heat and temperature and also bond energy. Investigates both a neutralization experiment and a ligation experiment. Notes inexpensive chemicals are used along with simple equipment. Discusses the sharing of lab results for a single class value. (MVL)
Spectroelectrochemical Sensing of Aqueous Iron: An Experiment for Analytical Chemistry
ERIC Educational Resources Information Center
Shtoyko, Tanya; Stuart, Dean; Gray, H. Neil
We have designed a laboratory experiment to illustrate the use of spectroelectrochemical techniques for determination of aqueous iron. The experiment described in this article is applicable to an undergraduate laboratory course in analytical chemistry. Students are asked to fabricate spectroelectrochemical sensors, make electrochemical and optical…
Organic N-chloramines: chemistry and toxicology.
Scully, F E; Bempong, M A
The stability of aqueous solutions of organic N-chloramines, suspected of contaminating chlorinated water, has been studied. Two factors influence the decomposition of solutions of N-chloropiperidine and N-chlorodiethylamine: a spontaneous decomposition and photodecomposition. Since solutions of these compounds are relatively long-lived, a need for an analytical method for their identification is discussed. A new method is described which involves reaction of organic N-chloramines with arenesulfinic acid salts. The method gives high yields of stable arenesulfonamides. Several toxicological studies of N-chloropiperidine are described. The compound is mutagenic by Ames assay in Salmonella typhimurium strain TA 100 and does not require metabolic activation as indicated in a total body fluids analysis using C57BL/J6 mice. N-Chloropiperidine was subjected to a modified in vitro cell transformation assay using diploid fibroblast cells from Syrian hamster fetuses. A maximum number of foci of 4 per dish was observed at a seeding of 5 X 10(3) cells/60 mm dish. Under similar conditions, MNNG-induced foci ranged from 4 to 7 per dish. PMID:7151751
Detection of Organics at Mars: How Wet Chemistry Onboard SAM Helps
NASA Technical Reports Server (NTRS)
Buch, A.; Freissinet, Caroline; Szopa, C.; Glavin, D.; Coll, P.; Cabane, M.; Eigenbrode, J.; Navarro-Gonzalez, R.; Coscia, D.; Teinturier, S.; Mahaffy, P.
For the first time in the history of space exploration, a mission of interest to astrobiology could be able to analyze refractory organic compounds in the soil of Mars. Wet chemistry experiment allow organic components to be altered in such a way that improves there detection either by releasing the compounds from sample matricies or by changing the chemical structure to be amenable to analytical conditions. The latter is particular important when polar compounds are present. Sample Analysis at Mars (SAM), on the Curiosity rover of the Mars Science Laboratory mission, has onboard two wet chemistry experiments: derivatization and thermochemolysis. Here we report on the nature of the MTBSTFA derivatization experiment on SAM, the detection of MTBSTFA in initial SAM results, and the implications of this detection.
Planetary Organic Chemistry and the Origins of Biomolecules
Benner, Steven A.; Kim, Hyo-Joong; Kim, Myung-Jung; Ricardo, Alonso
Organic chemistry on a planetary scale is likely to have transformed carbon dioxide and reduced carbon species delivered to an accreting Earth. According to various models for the origin of life on Earth, biological molecules that jump-started Darwinian evolution arose via this planetary chemistry. The grandest of these models assumes that ribonucleic acid (RNA) arose prebiotically, together with components for compartments that held it and a primitive metabolism that nourished it. Unfortunately, it has been challenging to identify possible prebiotic chemistry that might have created RNA. Organic molecules, given energy, have a well-known propensity to form multiple products, sometimes referred to collectively as "tar" or "tholin." These mixtures appear to be unsuited to support Darwinian processes, and certainly have never been observed to spontaneously yield a homochiral genetic polymer. To date, proposed solutions to this challenge either involve too much direct human intervention to satisfy many in the community, or generate molecules that are unreactive "dead ends" under standard conditions of temperature and pressure. Carbohydrates, organic species having carbon, hydrogen, and oxygen atoms in a ratio of 1:2:1 and an aldehyde or ketone group, conspicuously embody this challenge. They are components of RNA and their reactivity can support both interesting spontaneous chemistry as part of a "carbohydrate world," but they also easily form mixtures, polymers and tars. We describe here the latest thoughts on how on this challenge, focusing on how it might be resolved using minerals containing borate, silicate, and molybdate, inter alia. PMID:20504964
[Alcaloids discovery, markers for the history of organic chemistry].
Fournier, J
The development of organic chemistry is well fitted by the history of dyes. Are alkaloids as good markers? In 1876, Chevreul distinguished two steps in the history of these organic alkalis. The first began with Derosne who analyzed opium in 1803, followed by Seguin and mainly Sertuerner. It was closed about 1820 with Pelletier and Caventou researches, including works of Robiquet and Gomes from Lisbon. Next years, chemists investigated properties and chemical structures. With Pasteur, alkaloids participated to the emergence of stereochemistry, and with Claude Bernard, to the birth of a new science, physiology. Chevreul could not anticipate success of organic synthesis which blooms during the XXth century. PMID:11776272
Nuclear Experiments in the Chemistry Curriculum
ERIC Educational Resources Information Center
Clark, Herbert M.
Describes nuclear teaching experiments and their distribution within the undergraduate curriculum. In addition, sources of information on published nuclear teaching experiments and on the supplier's of nuclear instruments, radiochemical and miscellaneous special materials are identified. Approximate costs for selected nuclear instrument systems…
Photoelectroconversion by Semiconductors: A Physical Chemistry Experiment.
ERIC Educational Resources Information Center
Fan, Qinbai; And Others
Presents an experiment designed to give students some experience with photochemistry, electrochemistry, and basic theories about semiconductors. Uses a liquid-junction solar cell and illustrates some fundamental physical and chemical principles related to light and electricity interconversion as well as the properties of semiconductors. (JRH)
Integration of Computational and Preparative Techniques to Demonstrate Physical Organic Concepts in Synthetic Organic Chemistry: An Example Using Diels-Alder Reaction
ERIC Educational Resources Information Center
Palmer, David R. J.
The Diels-Alder reaction is used as an example for showing the integration of computational and preparative techniques, which help in demonstrating the physical organic concepts in synthetic organic chemistry. These experiments show that the students should not accept the computational results without questioning them and in many Diels-Alder…
Infusing the Chemistry Curriculum with Green Chemistry Using Real-World Examples, Web Modules, and Atom Economy in Organic Chemistry Courses
ERIC Educational Resources Information Center
Cann, Michael C.; Dickneider, Trudy A.
Green chemistry is the awareness of the damaging environmental effects due to chemical research and inventions. There is emphasis on a need to include green chemistry in synthesis with atom economy in organic chemistry curriculum to ensure an environmentally conscious future generation of chemists, policy makers, health professionals and business…
A Forty Year Odyssey in Metallo-Organic Chemistry.
Nicholas, Kenneth M
In this invited Perspective, I provide a personal account highlighting several of my group's research contributions in metallo-organic chemistry over the past 40 years. Our early work focused primarily in stoichiometric structure/reactivity of transition metal-organic compounds and their use in organic synthesis. More recent efforts have centered on the discovery and development of new metal-catalyzed organic reactions via reactive metal-organic intermediates. The major research findings that are described here include (1) propargyl-cobalt complexes as electrophilic agents for C-C and C-Nu coupling; (2) the activation of carbon dioxide by metal complexes; (3) metal-promoted C-H nitrogenation reactions; (4) oxo-metal catalyzed deoxygenation reactions; and (5) catalyst discovery via dynamic templating with substrate- and transition-state analogues. PMID:26035082
Tropospheric Chemistry of Internally Mixed Sea Salt and Organic Particles: Surprising Reactivity of NaCl with Weak Organic Acids
Laskin, Alexander; Moffet, Ryan C.; Gilles, Marry K.; Fast, Jerome D.; Zaveri, Rahul A.; Wang, Bingbing; Nigge, P.; Shutthanandan, Janani I.
Chemical imaging analysis of internally mixed sea salt/organic particles collected on board the Department of Energy (DOE) G-1 aircraft during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) was performed using electron microscopy and X-ray spectro-microscopy techniques. Substantial chloride depletion in aged sea salt particles was observed, which could not be explained by the known atmospheric reactivity of sea salt with inorganic nitric and sulfuric acids. We present field evidence that chloride components in sea salt particles may effectively react with organic acids releasing HCl gas to the atmosphere, leaving behind particles depleted in chloride and enriched in the corresponding organic salts. While formation of the organic salts products is not thermodynamically favored for bulk aqueous chemistry, these reactions in aerosol are driven by high volatility and irreversible evaporation of the HCl product from drying particles. These field observations were corroborated in a set of laboratory experiments where NaCl particles mixed with organic acids were found to be depleted in chloride. Combined together, the results indicate substantial chemical reactivity of sea salt particles with secondary organics that has been largely overlooked in the atmospheric aerosol chemistry. Atmospheric aging, and especially hydration-dehydration cycles of mixed sea salt/organic particles may result in formation of organic salts that will modify acidity, hygroscopic and optical properties of aged particles.
Tropospheric chemistry of internally mixed sea salt and organic particles: Surprising reactivity of NaCl with weak organic acids
NASA Astrophysics Data System (ADS)
Laskin, Alexander; Moffet, Ryan C.; Gilles, Mary K.; Fast, Jerome D.; Zaveri, Rahul A.; Wang, Bingbing; Nigge, Pascal; Shutthanandan, Janani
Chemical imaging analysis of internally mixed sea salt/organic particles collected onboard the Department of Energy (DOE) G-1 aircraft during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) was performed using electron microscopy and X-ray spectro-microscopy. Substantial chloride depletion in aged sea salt particles was observed, which could not be explained by the known atmospheric reactivity of sea salt with inorganic nitric and sulfuric acids. We present field evidence that chloride components in sea salt particles may effectively react with organic acids releasing HCl gas to the atmosphere, leaving behind particles depleted in chloride and enriched in the corresponding organic salts. While formation of the organic salts products is not thermodynamically favored for bulk aqueous chemistry, these reactions in aerosol are driven by high volatility and evaporation of the HCl product from drying particles. These field observations were corroborated in a set of laboratory experiments where NaCl particles mixed with organic acids were found to be depleted in chloride. Combined together, the results indicate substantial chemical reactivity of sea salt particles with secondary organics that has been largely overlooked in the atmospheric aerosol chemistry. Atmospheric aging, and in particular hydration-dehydration cycles of mixed sea salt/organic particles, may result in formation of organic salts that will modify the acidity, hygroscopic, and optical properties of aged particles.
Organic Chemistry in the Saturn System: Titan and Enceladus
Kaiser, Ralf I.
Organic Chemistry in the Saturn System: Titan and Enceladus J. H. Waite J. Westlake B. Magee T4 Saturn 1.7 (+0.75/0.45) x 105 Jupiter 2.25±0.35 x 105 Protosolar 2.1±0.4 x 105 D/H Cometary Were parIally devolaIlized in the early Saturn nebula, losing CO, N2, and Ar, but not CH4 Mousis et al
Nickel-Catalyzed Suzuki-Miyaura Cross-Coupling in a Green Alcohol Solvent for an Undergraduate Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Hie, Liana; Chang, Jonah J.; Garg, Neil K.
A modern undergraduate organic chemistry laboratory experiment involving the Suzuki-Miyaura coupling is reported. Although Suzuki-Miyaura couplings typically employ palladium catalysts in environmentally harmful solvents, this experiment features the use of inexpensive nickel catalysis, in addition to a "green" alcohol solvent. The…
Solution Calorimetry Experiments for Physical Chemistry.
ERIC Educational Resources Information Center
Raizen, Deborah A.; And Others
Presents two experiments: the first one measures the heat of an exothermic reaction by the reduction of permanganate by the ferris ion; the second one measures the heat of an endothermic process, the mixing of ethanol and cyclohexane. Lists tables to aid in the use of the solution calorimeter. (MVL)
Technetium Chemistry in HLW: Role of Organic Complexants
Hess, Nancy J.; Blanchard, David L., Jr.; Cho, Herman M.; Xia, Yuanxian; Campbell, James A.; Rai, Dhanpat; Conradson, Steven D.
Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. Technetium is thought to have followed U in bismuth phosphate, REDOX and PUREX extraction campaigns and the Cs and Sr isotope recovery efforts. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry. The fate of Tc in the insoluble salts that constitute tank residuals is of paramount importance due to the long half-life and environmental mobility of Tc. Knowledge gaps include determination of the Tc oxidation state, the stability of reduced Tc solution species, and interactions with possible organic complexants in HLW. The objective of this renewal proposal is to continue to pursue fundamental understanding of Tc solution chemistry that provides the basis to make knowledgeable decisions and predictions of Tc behavior during retrieval operations and in tank residuals.
Spectroscopic diagnostics of organic chemistry in the protostellar environment
NASA Technical Reports Server (NTRS)
Charnley, S. B.; Ehrenfreund, P.; Kuan, Y. J.
A combination of astronomical observations, laboratory studies, and theoretical modelling is necessary to determine the organic chemistry of dense molecular clouds. We present spectroscopic evidence for the composition and evolution of organic molecules in protostellar environments. The principal reaction pathways to complex molecule formation by catalysis on dust grains and by reactions in the interstellar gas are described. Protostellar cores, where warming of dust has induced evaporation of icy grain mantles, are excellent sites in which to study the interaction between gas phase and grain-surface chemistries. We investigate the link between organics that are observed as direct products of grain surface reactions and those which are formed by secondary gas phase reactions of evaporated surface products. Theory predicts observable correlations between specific interstellar molecules, and also which new organics are viable for detection. We discuss recent infrared observations obtained with the Infrared Space Observatory, laboratory studies of organic molecules, theories of molecule formation, and summarise recent radioastronomical searches for various complex molecules such as ethers, azaheterocyclic compounds, and amino acids.
UNESCO Chemistry Teaching Project in Asia: Experiments on Nuclear Science.
ERIC Educational Resources Information Center
Dhabanandana, Salag
This teacher's guide on nuclear science is divided into two parts. The first part is a discussion of some of the concepts in nuclear chemistry including radioactivity, types of disintegration, radioactive decay and growth, and tracer techniques. The relevant experiments involving the use of radioisotopes are presented in the second part. The…
A Physical Chemistry Experiment in Polymer Crystallization Kinetics
ERIC Educational Resources Information Center
Singfield, Kathy L.; Chisholm, Roderick A.; King, Thomas L.
A laboratory experiment currently used in an undergraduate physical chemistry lab to investigate the rates of crystallization of a polymer is described. Specifically, the radial growth rates of typical disc-shaped crystals, called spherulites, growing between microscope glass slides are measured and the data are treated according to polymer…
Global phosgene observations from the Atmospheric Chemistry Experiment (ACE) mission
Nassar, Ray
Global phosgene observations from the Atmospheric Chemistry Experiment (ACE) mission Dejian Fu,1 2007. [1] The first study of the global distribution of atmospheric phosgene (COCl2) has been performed in the study. The phosgene concentrations display a zonally symmetric pattern with the maximum concentration
Chemistry and Flatulence: An Introductory Enzyme Experiment
NASA Astrophysics Data System (ADS)
Hardee, John R.; Montgomery, Tina M.; Jones, Wray H.
An inexpensive introductory-level enzyme experiment was developed using raffinose family sugars extracted from green split peas as a substrate and the enzymes alpha-galactosidase and sucrase found in Beano. The reaction studied was the hydrolysis of raffinose family sugars to galactose, glucose, and fructose, and the reaction rate was determined using a retail glucometer to measure the concentration of glucose. Results are given on the effect of substrate concentration, enzyme concentration, temperature, and heavy metals on enzyme activity.
Admission for Ph.D. study is offered to students with good undergraduate training in biochemistry, physics, organic chemistry, physical chemistry, biology, and mathematics.
Sharp, Kim
in biochemistry, physics, organic chemistry, physical chemistry, biology, and mathematics. Students lacking Test is required; GRE Subject tests in biology, biochemistry, chemistry, physics or mathematics Hughes Medical Institute. Applicants are urged to apply for scholarships from the National Science
Spanish-Speaking English Language Learners' Experiences in High School Chemistry Education
ERIC Educational Resources Information Center
Flores, Annette; Smith, K. Christopher
This article reports on the experiences of Spanish-speaking English language learners in high school chemistry courses, focusing largely on experiences in learning the English language, experiences learning chemistry, and experiences learning chemistry in the English language. The findings illustrate the cognitive processes the students undertake…
A Self-Study, One-Paced Basic Organic Chemistry Course.
ERIC Educational Resources Information Center
Shani, Arnon; Singerman, Amnon
Following the description of a college organic chemistry course involving self-study and small group classroom work, summarizes five years of teaching the course (1976-1980) to chemistry majors. (Author/SK)
Tholins: Organic chemistry of interstellar grains and gas
NASA Technical Reports Server (NTRS)
Sagan, C.; Khare, B. N.
A complex organic solid produced from cosmically abundant molecules explains many properties of the interstellar grains and gas. The product, a brown, sometimes sticky residue that is resistant to conventional analytic chemistry, has been named tholins and is discussed as a major constituent of the interstellar medium. Sequential and nonsequential pyrolysis followed by gas chromatography/mass spectroscopy were used to determine something of the composition of this material. The production and properties of tholins produced by spark discharges and by ultraviolet light are examined.
The Book History I began writing this organic chemistry text in 1992 while I was a chemistry faculty member at
Reed, Christopher A.
The Book History I began writing this organic chemistry text in 1992 while I was a chemistry the complete book and then see if there was a publisher interested in it. Along the way things happened. A good progressed, I settled on a book with 23 chapters. Of those 23 chapters, I have "finished" all except Chapter
Synthesis of a Partially Protected Azidodeoxy Sugar. A Project Suitable for the Advanced Undergraduate Organic Chemistry Laboratory
NASA Astrophysics Data System (ADS)
Norris, Peter; Freeze, Scott; Gabriel, Christopher J.
The synthetic chemistry of carbohydrates provides a wealth of possible experiments for the undergraduate organic chemistry laboratory. However, few appropriate examples have been developed to date. With this simple two-step synthesis of a partially protected azidodeoxy sugar, we demonstrate several important concepts introduced in undergraduate chemistry (alcohol activation, steric hindrance, nucleophilic substitution) while offering products that are readily amenable to analysis by high field NMR. Students are exposed to techniques such as monitoring reactions by TLC, workup of reaction mixtures, and isolation by flash chromatography. Suitable methods for analysis of products include NMR, IR, MS, and polarimetry.
The concentration, major fractions, and contribution of dissolved organic carbon (DOG) to stream chemistry were examined in two paired streams draining upland catchments in eastern Maine. oncentrations of DOC in East and West Bear Brooks were 183 +/- 73 and 169 +/- 70 umol CL-1 (...
NSDL National Science Digital Library
Quiz questions from the organic chemistry question bank provide students with an excellent opportunity to review key concepts.. The Organic topic focuses on the basics of organic chemistry that are taught in general chemistry.
Ceria-based solid catalysts for organic chemistry.
Vivier, Laurence; Duprez, Daniel
Ceria has been the subject of thorough investigations, mainly because of its use as an active component of catalytic converters for the treatment of exhaust gases. However, ceria-based catalysts have also been developed for different applications in organic chemistry. The redox and acid-base properties of ceria, either alone or in the presence of transition metals, are important parameters that allow to activate complex organic molecules and to selectively orient their transformation. Pure ceria is used in several organic reactions, such as the dehydration of alcohols, the alkylation of aromatic compounds, ketone formation, and aldolization, and in redox reactions. Ceria-supported metal catalysts allow the hydrogenation of many unsaturated compounds. They can also be used for coupling or ring-opening reactions. Cerium atoms can be added as dopants to catalytic system or impregnated onto zeolites and mesoporous catalyst materials to improve their performances. This Review demonstrates that the exceptional surface (and sometimes bulk) properties of ceria make cerium-based catalysts very effective for a broad range of organic reactions. PMID:20486156
Development and Implementation of a Two-Semester Introductory Organic-Bioorganic Chemistry Sequence: Conclusions from the First Six Years
ERIC Educational Resources Information Center
Goess, Brian C.
A two-semester second-year introductory organic chemistry sequence featuring one semester of accelerated organic chemistry followed by one semester of bioorganic chemistry is described. Assessment data collected over a six-year period reveal that such a course sequence can facilitate student mastery of fundamental organic chemistry in the first…
What Does the Acid Ionization Constant Tell You? An Organic Chemistry Student Guide
ERIC Educational Resources Information Center
Rossi, Robert D.
Many students find the transition from first-year general chemistry to second-year organic chemistry a daunting task. There are many reasons for this, not the least of which is their lack of a solid understanding and appreciation of the importance of some basic concepts and principles from general chemistry that play an extremely critical role in…
Spatial ability and its role in organic chemistry: A study of four organic courses
NASA Astrophysics Data System (ADS)
Pribyl, Jeffrey R.; Bodner, George M.
The relationship between spatial ability and performance in organic chemistry was studied in four organic chemistry courses designed for students with a variety of majors including agriculture, biology, health sciences, pre-med, pre-vet, pharmacy, medicinal chemistry, chemistry, and chemical engineering.Students with high spatial scores did significantly better on questions which required problem solving skills, such as completing a reaction or outlining a multi-step synthesis, and questions which required students to mentally manipulate two-dimensional representations of a molecule. Spatial ability was not significant, however, for questions which could be answered by rote memory or by the application of simple algorithms.Students who drew preliminary figures or extra figures when answering questions were more likely to get the correct answer. High spatial ability students were more likely to draw preliminary figures, even for questions that did not explicitly require these drawings. When questions required preliminary or extra figures, low spatial ability students were more likely to draw figures that were incorrect. Low spatial ability students were also more likely to draw structures that were lopsided, ill-proportioned, and nonsymmetric.The results of this study are interpreted in terms of a model which argues that high spatial ability students are better at the early stages of problem solving described as understanding the problem. A model is also discussed which explains why students who draw preliminary or extra figures for questions are more likely to get correct answers.
Reactive Heterogeneous Chemistry on Organic Aerosols: Two Case Studies
NASA Astrophysics Data System (ADS)
Abbatt, J.; Braban, C.; Broekhuizen, K.; Thornberry, T.; Thornton, J.
Two sets of laboratory studies will be discussed to illustrate the impact that heterogeneous chemistry involving tropospheric organic aerosols may have on both the gas-phase composition of the atmosphere and the chemical nature of the particles themselves. In the first case, the reactive uptake coefficient for the hydrolysis of dinitrogen pentoxide (N2O5) on organic aerosols has been measured in an entrained aerosol flow tube coupled to a Chemical-Ionization Mass Spectrometer (CIMS). The general observation is that the reaction on aqueous malonic acid aerosols behaves in an analogous manner to that on aqueous inorganic salts, i.e. the uptake coefficient shows a linear dependence on the particle water content up to 50% relative humidity (RH), at which point the effect saturates. In addition, there is evidence for the kinetics being dependent on both the size of the particles and the levels of dissolved nitrate. By contrast, the N2O5 hydrolysis kinetics on solid azelaic acid particles are too slow to be atmospherically significant, even at 85% RH. In the second case, the kinetics and product yields from the oxidation of liquid oleic acid by ozone have been studied in considerable detail, with emphasis on the quantification of gas-phase products (nonanal) by CIMS and water-soluble species by HPLC/Electrospray-Ionization Mass Spectrometry (azelaic acid, nonanoic acid). The atmospheric importance of these results will be discussed, in particular with respect to the role of organic aerosol oxidation as a source of cloud condensation nuclei.
Ethanol Metabolism and the Transition from Organic Chemistry to Biochemistry
NASA Astrophysics Data System (ADS)
Feinman, Richard D.
To ease the transition from organic chemistry at the beginning of a biochemistry course or at the beginning of the metabolism section of the organic course, an early presentation of the oxidation of ethanol is proposed. Alcohol dehydrogenase and aldehyde dehydrogenase reactions can smooth the introduction to biochemistry, since they involve three of the simplest compounds: ethanol, acetaldehyde, and acetic acid. Using these reactions as a model encourages the study of metabolic pathways by a systematic approach rather than by rote memorization. Reactions that can be presented as variations on a theme include methanol poisoning, the polyol reaction, and, most important, the sequence glycerol-3-phosphate to glyceraldehyde-3-phosphate to 3-phosphoglyceric acid. This last sequence integrates lipid and carbohydrate metabolism and, by comparison with the model reaction, brings out the principles of substrate-level phosphorylation. The method has evoked favorable verbal feedback from students and, in addition to medical and graduate courses, has been successfully used in the biochemical section of an undergraduate organic course.
Organic Chemistry of the Cell: An Interdisciplinary Approach To Learning with a Focus on Reading, Analyzing, and Critiquing Primary Literature
NASA Astrophysics Data System (ADS)
Almeida, Craig A.; Liotta, Louis J.
A sophomore-level learning community entitled Organic Chemistry of the Cell has been designed that is comprised of two linked courses, Organic Chemistry I and Cell Biology, and an Integrative Seminar. The Integrative Seminar is grounded in the reading, critical analysis, and discussion of primary literature that ties together organic chemistry and cell biology. Each student takes on the roles of learner, facilitator, and research proposal writer throughout the semester. Students take an active role in their learning; student teams lead the class through an in-depth analysis of selected articles. This leadership role requires the students to understand and be familiar with the relevant background knowledge, the experiments conducted, the interpretation of data, and conclusions drawn from that data. The discussion leaders must also be able to organize and prioritize the information and their thoughts, and be able to clearly communicate to their classmates in an engaging manner. The seminar culminates with student teams developing research proposals that outline experiments addressing a specific area of interest on the boundary between organic chemistry and cell biology. The proposals are communicated in both written and oral forms allowing fellow students to evaluate and expand upon the proposed ideas.
Using Structure-Based Organic Chemistry Online Tutorials with Automated Correction for Student Practice and Review
ERIC Educational Resources Information Center
O'Sullivan, Timothy P.; Hargaden, Gra´inne C.
This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Dublin Institute of Technology. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing…
The Use of Computer-Based Instruction in Undergraduate Organic Chemistry.
ERIC Educational Resources Information Center
Culp, George H.
Thirty-two computer-based lesson modules in organic chemistry were developed at the University of Texas (Austin) over an 18-month period and evaluated in varying classroom situations for three semesters starting in the Fall of 1972. The modules were designed as supplements to the traditional organic chemistry course of the University. As such,…
for Undergraduate CHEMISTRY MAJORS
Stuart, Steven J.
and Petroleum Chemistry, Organic Chemistry, Physical Chemistry, Polymer Chemistry, Pulp and Paper Chemistry, RHANDBOOK for Undergraduate CHEMISTRY MAJORS DEPARTMENT OF CHEMISTRY Fall 2010 #12;#12;TABLE OF CONTENTS A Career in Chemistry - What It Means ___________________________________________ 4 What do
Comparing Recent Organizing Templates for Test Content between ACS Exams in General Chemistry and AP Chemistry
ERIC Educational Resources Information Center
Holme, Thomas
Two different versions of "big ideas" rooted content maps have recently been published for general chemistry. As embodied in the content outline from the College Board, one of these maps is designed to guide curriculum development and testing for advanced placement (AP) chemistry. The Anchoring Concepts Content Map for general chemistry…
Self-Organized Criticality: Theory and Experiment
Stefan Boettcher
Recent developments regarding driven dissipative systems that exhibit self-organized criticality (SOC) will be reviewed. While the concept of SOC has been proposed a decade ago to explain scale-free fluctuations found in many natural phenomena (such as earth quakes), it has been established in controlled experiments only recently. These experiments study granular motion in rice piles. We can show that these
The Deep Convective Clouds and Chemistry (DC3) Field Experiment
NASA Astrophysics Data System (ADS)
Barth, M. C.; Brune, W. H.; Cantrell, C. A.; Rutledge, S. A.; Crawford, J. H.; Huntrieser, H.; Homeyer, C. R.; Nault, B.; Cohen, R. C.; Pan, L.; Ziemba, L. D.
The Deep Convective Clouds and Chemistry (DC3) field experiment took place in the central U.S. in May and June 2012 and had the objectives of characterizing the effect of thunderstorms on the chemical composition of the lower atmosphere and determining the chemical aging of upper troposphere (UT) convective outflow plumes. DC3 employed ground-based radars, lightning mapping arrays, and weather balloon soundings in conjunction with aircraft measurements sampling the composition of the inflow and outflow of a variety of thunderstorms in northeast Colorado, West Texas to central Oklahoma, and northern Alabama. A unique aspect of the DC3 strategy was to locate and sample the convective outflow a day after active convection in order to measure the chemical transformations within the UT convective plume. The DC3 data are being analyzed to investigate transport and dynamics of the storms, scavenging of soluble trace gases and aerosols, production of nitrogen oxides by lightning, relationships between lightning flash rates and storm parameters, and chemistry in the UT that is affected by the convection. In this presentation, we give an overview of the DC3 field campaign and highlight results from the campaign that are relevant to the upper troposphere and lower stratosphere region. These highlights include stratosphere-troposphere exchange in connection with thunderstorms, the 0-12 hour chemical aging and new particle formation in the UT outflow of a dissipating mesoscale convective system observed on June 21, 2012, and UT chemical aging in convective outflow as sampled the day after convection occurred and modeled in the Weather Research and Forecasting coupled with Chemistry model.
The Influence of First-Year Chemistry Students' Learning Experiences on Their Educational Choices
ERIC Educational Resources Information Center
Dalgety, Jacinta; Coll, Richard K.
The research reported here examined factors that influence student tertiary level chemistry enrolment choices. Students enrolled in a first-year chemistry class were surveyed, using the Chemistry Attitudes and Experiences Questionnaire (CAEQ), three times throughout their academic year: at the start of the year (n=126), the end of the first…
Fulminic Acid in the History of Organic Chemistry
NASA Astrophysics Data System (ADS)
Kurzer, Frederick
The story of the discovery, investigation, and eventual correct formulation of fulminic acid, HCNO, extends over a period of 200 years and reflects uniquely, in its many stages, the evolution of organic chemistry from post-alchemistic times to the age of wave mechanics. Fulminic acid was discovered in 1800 when E. Howard serendipitously prepared its highly explosive mercury and silver salts. The determination of its structure presented unusual difficulties and taxed the ingenuity of leading chemists of successive generations. Their work generated a procession of proposed and discarded formulations that was only finally ended in the 1960s with the recognition of fulminic acid as the mesomeric structure and hence with its identification as the parent compound of the important class of the nitrile N-oxides. Recently fulminic acid and several of its isotopomers have been subjected to the most searching spectroscopic investigations and ab initio computations, by which its molecular dimensions and geometry, and its "quasi-linear" structure have been revealed. In technology, mercury fulminate occupied for nearly a century a uniquely important position as the only available practical detonator for every kind of conventional explosive.
Lunar carbon chemistry - Relations to and implications for terrestrial organic geochemistry.
NASA Technical Reports Server (NTRS)
Eglinton, G.; Maxwell, J. R.; Pillinger, C. T.
Survey of the various ways in which studies of lunar carbon chemistry have beneficially affected terrestrial organic geochemistry. A lunar organic gas-analysis operating system is cited as the most important instrumental development in relation to terrestrial organic geochemistry. Improved methods of analysis and handling of organic samples are cited as another benefit derived from studies of lunar carbon chemistry. The problem of controlling contamination and minimizing organic vapors is considered, as well as the possibility of analyzing terrestrial samples by the techniques developed for lunar samples. A need for new methods of analyzing carbonaceous material which is insoluble in organic solvents is indicated.
Global phosgene observations from the Atmospheric Chemistry Experiment (ACE) mission
NASA Astrophysics Data System (ADS)
Fu, Dejian; Boone, Chris D.; Bernath, Peter F.; Walker, Kaley A.; Nassar, Ray; Manney, Gloria L.; McLeod, Sean D.
The first study of the global distribution of atmospheric phosgene (COCl2) has been performed using solar occultation measurements from the Atmospheric Chemistry Experiment (ACE) satellite mission. A total of 5614 measured profiles spanning the period February 2004 through May 2006 were used in the study. The phosgene concentrations display a zonally symmetric pattern with the maximum concentration located approximately over the equator at about 25 km in altitude and the concentration decreases towards the poles. A layer of enhanced concentration of phosgene spans the lower stratosphere over all latitudes, with volume mixing ratios of 20-60 pptv. The ACE observations show lower phosgene concentrations in the stratosphere than were obtained from previous observations in the 1980s and 1990s. This has been attributed to a significant decrease in its source species, particularly two major sources CH3CCl3 and CCl4, since the introduction of restrictions required by the Montreal Protocol and its amendments.
The Integration of Green Chemistry Experiments with Sustainable Development Concepts in Pre-Service Teachers' Curriculum: Experiences from Malaysia
ERIC Educational Resources Information Center
Karpudewan, Mageswary; Ismail, Zurida Hg; Mohamed, Norita
Purpose: The purpose of this paper is to introduce green chemistry experiments as laboratory-based pedagogy and to evaluate effectiveness of green chemistry experiments in delivering sustainable development concepts (SDCs) and traditional environmental concepts (TECs). Design/methodology/approach: Repeated measure design was employed to evaluate…
Students' Understanding of Acids/Bases in Organic Chemistry Contexts
ERIC Educational Resources Information Center
Cartrette, David P.; Mayo, Provi M.
Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…
A Laboratory Experiment To Measure Henry's Law Constants of Volatile Organic Compounds with a Bubble Column and a Gas
Lee, Shan-Hu
/Manipulatives, Atmospheric Chemistry, Equilibrium, Thermodynamics Henry's law constant represents the solubility of a soluteA Laboratory Experiment To Measure Henry's Law Constants of Volatile Organic Compounds experiment is described to measure Henry's law constants of organic compounds using a bubble column and gas
A Collaborative, Wiki-Based Organic Chemistry Project Incorporating Free Chemistry Software on the Web
ERIC Educational Resources Information Center
Evans, Michael J.; Moore, Jeffrey S.
In recent years, postsecondary instructors have recognized the potential of wikis to transform the way students learn in a collaborative environment. However, few instructors have embraced in-depth student use of chemistry software for the creation of interactive chemistry content on the Web. Using currently available software, students are able…
An Asymptotic Approach to the Development of a Green Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Goodwin, Thomas E.
Green chemistry is the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products. Some of the philosophical questions and practical decisions that have guided the greening of the organic chemistry laboratory at Hendrix College in…
Ethnically Diverse Students' Knowledge Structures in First-Semester Organic Chemistry
ERIC Educational Resources Information Center
Lopez, Enrique J.; Shavelson, Richard J.; Nandagopal, Kiruthiga; Szu, Evan; Penn, John
Chemistry courses remain a challenge for many undergraduate students. In particular, first-semester organic chemistry has been labeled as a gatekeeper with high attrition rates, especially among students of color. Our study examines a key factor related to conceptual understanding in science and predictive of course outcomes-knowledge structures.…
Intuitive Judgments Govern Students' Answering Patterns in Multiple-Choice Exercises in Organic Chemistry
ERIC Educational Resources Information Center
Graulich, Nicole
Research in chemistry education has revealed that students going through their undergraduate and graduate studies in organic chemistry have a fragmented conceptual knowledge of the subject. Rote memorization, rule-based reasoning, and heuristic strategies seem to strongly influence students' performances. There appears to be a gap between what we…
The Tip of the Iceberg in Organic Chemistry Classes: How Do Students Deal with the Invisible?
ERIC Educational Resources Information Center
Graulich, Nicole
Organic chemistry education is one of the youngest research areas among all chemistry related research efforts, and its published scholarly work has become vibrant and diverse over the last 15 years. Research on problem-solving behavior, students' use of the arrow-pushing formalism, the investigation of students' conceptual knowledge and…
Development and Application of a Scoring Rubric for Evaluating Students' Experimental Skills in Organic Chemistry: An Instructional Guide for Teaching Assistants
ERIC Educational Resources Information Center
Chen, Hui-Jung; She, Jui-Lin; Chou, Chin-Cheng; Tsai, Yeun-Min; Chiu, Mei-Hung
The purpose of this study was to develop a scoring rubric to assess students' manipulation skills and identify students' learning difficulties in conducting organic chemistry experiments. In constructing the scoring rubric, we first analyzed the skills needed in the experiment, then divided the skills into subskills, and finally…
Synthetic biology: lessons from the history of synthetic organic chemistry.
Yeh, Brian J; Lim, Wendell A
The mid-nineteenth century saw the development of a radical new direction in chemistry: instead of simply analyzing existing molecules, chemists began to synthesize them--including molecules that did not exist in nature. The combination of this new synthetic approach with more traditional analytical approaches revolutionized chemistry, leading to a deep understanding of the fundamental principles of chemical structure and reactivity and to the emergence of the modern pharmaceutical and chemical industries. The history of synthetic chemistry offers a possible roadmap for the development and impact of synthetic biology, a nascent field in which the goal is to build novel biological systems. PMID:17710092
An Experiment to Quantitate Organically Bound Phosphate.
ERIC Educational Resources Information Center
Palmer, Richard E.
Describes quick and easy experiments that yield quantitative information on a variety of levels, emphasize the concept of experimental controls, and integrate the experimental with the theoretical using the organic phosphates as the experimental system. Background information, list of materials needed, and procedures used are included. (JN)
The influence of microbial communities, management, and soil texture on soil organic matter chemistry
Fierer, Noah
The influence of microbial communities, management, and soil texture on soil organic matter Accepted 3 February 2009 Available online 18 March 2009 Keywords: Soil organic matter Microbial communities in organic matter chemistry was linked to management, soil edaphic properties, microbial communities
Organic nitrogen chemistry during low-grade metamorphism Jean-Paul Boudou
Paris-Sud XI, Université de
Organic nitrogen chemistry during low-grade metamorphism Jean-Paul Boudou a *, Arndt Schimmelmann firstname.lastname@example.com Abstract - Most of the organic nitrogen (Norg) on Earth is disseminated in crustal sediments and rocks in the form of fossil nitrogen-containing organic matter. The chemical speciation of fossil Norg within
Faculty of Science Chemistry is the study of matter -
and laboratory experience in the general sub-disciplines of chemistry: · Organic Chemistry · Physical Chemistry Differential Calculus Introductory Physics I Arts or Social Science Elective General Chemistry II BiologicalFaculty of Science Chemistry Chemistry is the study of matter - anything that has mass and occupies
Microwave-Assisted Chemistry: A Rapid and Sustainable Route to Synthesis of Organics and Nanomaterials
The use of emerging MW-assisted chemistry techniques in conjunction with benign reaction media is dramatically reducing chemical waste and reaction times in several organic syntheses and chemical transformations. This review summarizes recent developments in MW-assisted synthesis...
Beilstein Without Tears: Education in the Use of the Literature of Organic Chemistry.
ERIC Educational Resources Information Center
Callaghan, Patricia M.; And Others
The use of Beilstein ("Handbuch der Organischen Chemie") in the early stages of a second-year, one semester course in organic chemistry is described. Student literature projects, evaluation, use of ancillary literature, and a sample search are included. (JN)
Teaching a Modified Hendrickson, Cram, and Hammond Curriculum in Organic Chemistry
ERIC Educational Resources Information Center
Karty, Joel M.; Gooch, Gene; Bowman, B. Gray
A modified Hendrickson, Cram and Hammond (HCH) curriculum was recently introduced in the study of organic chemistry. The approach focuses on the fundamentals and is found to have a lot of positive impact on the students.
Incorporating a Substantial Writing Assignment into Organic Chemistry: Library Research, Peer Review, and Assessment
NASA Astrophysics Data System (ADS)
Shibley, Ivan A., Jr.; Milakofsky, Louis K.; Nicotera, Cynthia L.
A substantial writing assignment in an organic chemistry course provides a means of allowing students to direct their own learning about a specific application of organic chemistry. The use of peer review provided additional benefits: students learned organic chemistry from reading each others' papers and learned more about how classmates write about chemistry. Recommendations about how best to collaborate with a librarian in the design of a writing assignment that involves substantial library research are presented. One of the main features of effective assignments is the statement of clear expectations about assessment of the writing. The explicit criteria used to grade the papers are described. A substantial writing assignment such as this one can provide a means of moving an organic course from instructor-centered to student-centered.
Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students
ERIC Educational Resources Information Center
Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.
This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…
Guided-Inquiry Experiments for Physical Chemistry: The POGIL-PCL Model
ERIC Educational Resources Information Center
Hunnicutt, Sally S.; Grushow, Alexander; Whitnell, Robert
The POGIL-PCL project implements the principles of process-oriented, guided-inquiry learning (POGIL) in order to improve student learning in the physical chemistry laboratory (PCL) course. The inquiry-based physical chemistry experiments being developed emphasize modeling of chemical phenomena. In each experiment, students work through at least…
Implementation of Lab VIEW for Computer-Controlled Experiments in General Chemistry Laboratory Instruction
Adam Allerhand; Alice Dobie-Galuska
A case is made for the pedagogical advantages of standardizing on LabVIEW-based computer-controlled experiments in introductory chemistry laboratory instruction. Experiments already in use, some for several years, in courses with large enrollments are described.
Usnic Acid and the Intramolecular Hydrogen Bond: A Computational Experiment for the Organic Laboratory
ERIC Educational Resources Information Center
Green, Thomas K.; Lane, Charles A.
A computational experiment is described for the organic chemistry laboratory that allows students to estimate the relative strengths of the intramolecular hydrogen bonds of usnic and isousnic acids, two related lichen secondary metabolites. Students first extract and purify usnic acid from common lichens and obtain [superscript 1]H NMR and IR…
ATR-FTIR Spectroscopy in the Undergraduate Chemistry Laboratory: Part II--A Physical Chemistry Laboratory Experiment on Surface Adsorption
ERIC Educational Resources Information Center
Schuttlefield, Jennifer D.; Larsen, Sarah C.; Grassian, Vicki H.
Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is a useful technique for measuring the infrared spectra of solids and liquids as well as probing adsorption on particle surfaces. The use of FTIR-ATR spectroscopy in organic and inorganic chemistry laboratory courses as well as in undergraduate research was presented…
Special Topics in Organic Chemistry 8833A Pulping and Bleaching Chemistry
Sherrill, David
. The focus is on alkaline/NaSH pulping and ClO2, H2O2, O2/NaOH, O3 bleaching chemistry of chemical and carbohydrates with - Chlorine-containing reagents (i.e., Cl2 and ClO2) - Oxygen-based reagents (i.e. H2O2, O2/NaOH, activated peroxide and O3) Student Seminars describing the fundamental chemistry, conformation, synthesis
Organism support for life sciences spacelab experiments
NASA Technical Reports Server (NTRS)
Drake, G. L.; Heppner, D. B.
This paper presents an overview of the U.S. life sciences laboratory concepts envisioned for the Shuttle/Spacelab era. The basic development approach is to provide a general laboratory facility supplemented by specific experiment hardware as required. The laboratory concepts range from small carry-on laboratories to fully dedicated laboratories in the Spacelab pressurized module. The laboratories will encompass a broad spectrum of research in biology and biomedicine requiring a variety of research organisms. The environmental control and life support of these organisms is a very important aspect of the success of the space research missions. Engineering prototype organism habitats have been designed and fabricated to be compatible with the Spacelab environment and the experiment requirements. These first-generation habitat designs and their subsystems have supported plants, cells/tissues, invertebrates, and small vertebrates in limited evaluation tests. Special handling and transport equipment required for the ground movement of the experiment organisms at the launch/landing site have been built and tested using these initial habitat prototypes.
The interfacial chemistry of organic materials on commercial glass surfaces
NASA Astrophysics Data System (ADS)
Banerjee, Joy
The hydrolytic stability of glass is dependent on its composition. Glasses are exposed to water during their processing and in many applications; therefore, their surface or interface with other materials must withstand hydrolytic attack. Multi-component silicate glasses are widely used but have been the least studied. In coatings-based applications, these glasses come in contact with organosilanes and organic molecules where the adsorption may be affected by surface water. For example, the influence of glass composition on the wet strength of a glass/polymer composite material is unclear, but it is presumed to be driven by the hydrolytic stability of the interfacial chemistry. Organosilanes are critical for increasing the performance of composite materials in humid environments but the precise manner by which the improvement occurs has not been verified. The current school of thought is that the application of silane coatings on a multi-component glass surface transforms the chemically heterogeneous surface into a homogenous and hydrolytically stable surface. In this study, multi-component silicate glass surfaces were silanized by both aqueous and non-aqueous methods. The effect of glass composition and surface hydration on silane coverage was quantified by X-ray Photoelectron Spectroscopy (XPS) analysis. The monolayer-level adsorption results showed that the low-sodium content glasses had greater coverage than a high-sodium content glass in dry conditions in contrast to an equivalent coverage in wet conditions. The hydrolytically-stable coverage on multi-component silicate glass surfaces by both silanization methods was found to be sub-monolayer. A thin film model in conjunction with XPS and Infrared Spectroscopy was used to probe the interfacial region of a fiberglass insulation material containing a sodium-rich multi-component silicate glass and an acrylate resin binder. Upon the application of the aqueous binder, the leaching of sodium from the glass promoted the formation of sodium carboxylate salts that were found to be detrimental to the hydrolytic stability of the interfacial region. The silanization of the glass improved the hydrolytic stability of the interfacial region by the mitigation of sodium carboxylate salt formation. The lack of interfacial failure indicated that the adsorption of the silane molecules and their interactions with the resin binder were hydrolytically stable.
Laboratory experiments in the study of the chemistry of the outer planets
NASA Technical Reports Server (NTRS)
Scattergood, Thomas W.
It is shown that much information about planetary chemistry and physics can be gained through laboratory work. The types of experiments relevant to planetary research concern fundamental properties, spectral/optical properties, 'Miller-Urey' syntheses, and detailed syntheses. Specific examples of studies of the chemistry in the atmosphere of Titan are described with attention given to gas phase chemistry in the troposphere and the composition of model Titan aerosols. A list of work that still needs to be done is provided.
On the Applicability of the Green Chemistry Principles to Sustainability of Organic Matter on Asteroids
NASA Astrophysics Data System (ADS)
Kolb, Vera M.
The connection between astrobiology and green chemistry represents a new approach to sustainability of organic matter on asteroids or similar bodies. Green chemistry is chemistry which is environmentally friendly. One obvious way for chemistry to be green is to use water as a solvent, instead of more toxic organic solvents. Many astrobiological reactions occur in the aqueous medium, for example in the prebiotic soup or during the aqueous alteration period on asteroids. Thus any advances in the green organic reactions in water are directly applicable to astrobiology. Another green chemistry approach is to abolish use of toxic solvents. This can be accomplished by carrying out the reactions without a solvent in the solventless or solid-state reactions. The advances in these green reactions are directly applicable to the chemistry on asteroids during the periods when water was not available. Many reactions on asteroids may have been done in the solid mixtures. These reactions may be responsible for a myriad of organic compounds that have been isolated from the meteorites.
Assessment of SAPRC07 with updated isoprene chemistry against outdoor chamber experiments
NASA Astrophysics Data System (ADS)
Chen, Yuzhi; Sexton, Kenneth G.; Jerry, Roger E.; Surratt, Jason D.; Vizuete, William
Isoprene, the most emitted non-methane hydrocarbon, is known to influence ozone (O3) formation in urban areas rich with biogenic emissions. To keep up with the recent advance on isoprene oxidation chemistry including the identification of isoprene epoxydiols (IEPOX) as a precursor to secondary organic aerosol (SOA), Xie et al. (2013) updated the SAPRC (Statewide Air Pollution Research Center)-07 chemical mechanism. It is currently unknown how the Xie modification of SAPRC07 impacts the ability of the model to predict O3. In this study we will evaluate the Xie mechanism with simulations of 24 isoprene experiments from the UNC Dual Gas-phase Chamber. Our results suggest that the new mechanism increases NOx (nitrogen oxides) inter-conversion and produces more O3 than SAPRC07 for all experiments. In lower-NOx experiments, the new mechanism worsens O3 performance in the wrong direction, increasing bias from 4.92% to 9.44%. We found increased NOx recycling from PANs accounts for that. This could be explained by more PANs made due to increased first generation volatile organic compound (VOC) products and hydroxyl radical (OH) production.
Microwave-Assisted Chemistry: a Rapid and Sustainable Route to Synthesis of Organics and Nanomaterials
Vivek Polshettiwar; A Mallikarjuna
The use of emerging microwave (MW)-assisted chemistry techniques in conjunction with benign reaction media is dramat- ically reducing chemical waste and reaction times in several organic syntheses and chemical transformations. The present review summarizes recent developments in MW-assisted synthesis, name reactions and organic transformations, and rapid generation of nanoparticles with uniform size distribution. Greener protocols have been developed for the
Do organic surface films on sea salt aerosols influence atmospheric chemistry? - a model study
L. Smoydzin; R. von Glasow
Organic material from the ocean's surface can be incorporated into sea salt aerosol particles often producing a surface film on the aerosol. Such an organic coating can reduce the mass transfer between the gas phase and the aerosol phase influencing sea salt chemistry in the marine atmosphere. To investigate these effects and their importance for the marine boundary layer (MBL)
Acid-Base Learning Outcomes for Students in an Introductory Organic Chemistry Course
ERIC Educational Resources Information Center
Stoyanovich, Carlee; Gandhi, Aneri; Flynn, Alison B.
An outcome-based approach to teaching and learning focuses on what the student demonstrably knows and can do after instruction, rather than on what the instructor teaches. This outcome-focused approach can then guide the alignment of teaching strategies, learning activities, and assessment. In organic chemistry, mastery of organic acid-base…
The Determination of Partial Specific Volume: A Physical Chemistry Experiment
ERIC Educational Resources Information Center
Sun, S. F.; Serpentino, Peter M.
Describes a method for the accurate determination of partial specific volume of a protein. Method is simple enough to include in the undergraduate physical chemistry laboratory but requires patience and careful handling which provide good training in laboratory techniques. (SLH)
Organic peroxide and OH formation in aerosol and cloud water: laboratory evidence for this aqueous chemistry
NASA Astrophysics Data System (ADS)
Lim, Y. B.; Turpin, B. J.
Aqueous chemistry in atmospheric waters (e.g., cloud droplets or wet aerosols) is well accepted as an atmospheric pathway to produce secondary organic aerosol (SOAaq). Water-soluble organic compounds with small carbon numbers (C2-C3) are precursors for SOAaq and products include organic acids, organic sulfates, and high molecular weight compounds/oligomers. Fenton reactions and the uptake of gas-phase OH radicals are considered to be the major oxidant sources for aqueous organic chemistry. However, the sources and availability of oxidants in atmospheric waters are not well understood. The degree to which OH is produced in the aqueous phase affects the balance of radical and non-radical aqueous chemistry, the properties of the resulting aerosol, and likely its atmospheric behavior. This paper demonstrates organic peroxide formation during aqueous photooxidation of methylglyoxal using ultra high resolution Fourier Transform Ion Cyclotron Resonance electrospray ionization mass spectrometry (FTICR-MS). Organic peroxides are known to form through gas-phase oxidation of volatile organic compounds. They contribute secondary organic aerosol (SOA) formation directly by forming peroxyhemiacetals, and epoxides, and indirectly by enhancing gas-phase oxidation through OH recycling. We provide simulation results of organic peroxide/peroxyhemiacetal formation in clouds and wet aerosols and discuss organic peroxides as a source of condensed-phase OH radicals and as a contributor to aqueous SOA.
Structure & Reactivity in Organic, Biological and Inorganic Chemistry
NSDL National Science Digital Library
Chris P. Schaller
This site is a collection of web-pages designed to support an integrated treatment of related topics from organic, inorganic and biochemistry. The topics are organized around common principles of structure or reactivity.
The role of high-pressure organic chemistry in planetary evolution
NASA Astrophysics Data System (ADS)
Montgomery, Wren Bowlan
Organic materials, containing only H, C, N, and O, are observed in proto- planetary discs, comets and meteorites, which provide the keys to understanding the early Earth. Direct study of two molecules common in these environments, formic acid (HCOOH) and cyanuric acid (H 3 C 3 N 3 O 3 ), has shown that these molecules survive to higher pressures and temperatures than expected and transform to more complex molecules, implying that high-pressure environments associated with young planets could be a key source of prebiotic molecules in the early Earth. Complementary models of generic planetary interiors have been undertaken, in order to better understand environments outside the Earth which could harbor prebiotic chemistry. To determine the stability, phase, and reaction limits of formic acid and cyanuric acid, Raman and Fourier transform infrared (FTIR) spectroscopy were used with heated diamond-anvil cell experiments. The melting curve of formic acid and two decomposition reactions were determined. A third solid-solid reaction was identified at higher pressures, with evidence of the formation of more complex molecules, recoverable to ambient conditions. The chemistry of cyanuric acid was shown to be more complex, with a decomposition reaction taking the place of a melting curve, and the formation of new molecules whose composition varies with the pressure at which the reaction occurs. These new molecules have been identified as di- and tri- substituted benzene molecules and heterocyclic aromatic molecules, a step towards more complex organized prebiotic chemistry. With the recent discovery of super-Earths orbiting other stars, data on planetary masses and radii outside our solar system is rapidly becoming available. The effects of self compression on the internal structure of planetary bodies are poorly understood. Planetary models using the second-order Birch- Murnaghan equation of state to model a spherical body under hydrostatic equilibrium were used to understand the effects of changing the material properties on astronomical observables such as the moment of inertia, radius and mass. The resulting density profiles help constrain the survival depths of organic materials in addition to providing mass vs. radius curves for planets of varying compositions. These mass vs. radius plots show that present mass- radius observations can help constrain the composition of an exoplanet.
Review of field use and corrosion experience with phosphate chemistry in nuclear steam generators
Although most PWRs changed to and are operated with all-volatile treatment (AVT) secondary chemistry control, San Onofre Unit 1, Jose Cabrera in Spain and the early vintage KWU built PWRs operated successfully with phosphate chemistry. Available experience reports indicated no significant secondary side initiated corrosion other than wastage had occurred, in contrast to IGA\\/IGSCC found at a large proportion of
Students Doing Chemistry: A Hand-On Experience for K-12
ERIC Educational Resources Information Center
Selco, Jodye I.; Bruno, Mary; Chan, Sue
A hands-on, minds-on inquiry chemistry experiment was developed for use in K-12 schools that enables students to combine the chemicals of their choice and observe the results. The chemistry involved is water based and builds upon acid-base, double displacement, and iodometric detection of starch reactions. Chemicals readily available in the…
Douglas Jay Lynch; Hernando Trujillo
Students enter college chemistry courses with different sources of motivation, appropriate or inappropriate assumptions about\\u000a their probability of success and how to study. This study is theoretically aligned with self-regulated learning research.\\u000a Clearly, academic performance is closely related to student motivational beliefs and learning strategies. This study investigated\\u000a the motivational beliefs and learning strategies of 2 years of college students in
Minimal impact of organic chemistry prerequisite on student performance in introductory biochemistry.
Wright, Robin; Cotner, Sehoya; Winkel, Amy
Curriculum design assumes that successful completion of prerequisite courses will have a positive impact on student performance in courses that require the prerequisite. We recently had the opportunity to test this assumption concerning the relationship between completion of the organic chemistry prerequisite and performance in introductory biochemistry. We found no statistically significant differences between average biochemistry grades or grade distribution among students with or without the organic chemistry prerequisite. However, students who had not completed the organic chemistry prerequisite before biochemistry were more likely to withdraw from the course than those who had completed the prerequisite. In contrast to the lack of correlation between performance in biochemistry and completion of organic chemistry, we observed a strong, highly significant positive relationship between cumulative GPA and the biochemistry grade. Our data suggest that excluding students without organic chemistry would have less positive impact on student success in biochemistry than would providing additional support for all students who enroll in biochemistry with a cumulative GPA below 2.5. PMID:19255135
Extraterrestrial organic chemistry: from the interstellar medium to the origins of life. Part 2: complex organic chemistry in the environment of planets and satellites.
Raulin, F; Kobayashi, K
During COSPAR'00 in Warsaw, Poland, in the frame of Sub-Commission F.3 events (Planetary Biology and Origins of Life), part of COSPAR Commission F (Life Sciences as Related to Space), and Commission B events (Space Studies of the Earth-Moon System, Planets, and Small Bodies of the Solar System) a large joint symposium (F.3.4/B0.8) was held on extraterrestrial organic chemistry. Part 2 of this symposium was devoted to complex organic chemistry in the environment of planets and satellites. The aim of this event was to cover and review new data which have been recently obtained and to give new insights on data which are expected in the near future to increase our knowledge of the complex organic chemistry occurring in several planets and satellites of the Solar System, outside the earth, and their implications for exobiology and life in the universe. The event was composed of two main parts. The first part was mainly devoted to the inner planets and Europa and the search for signatures of life or organics in those environments. The second part was related to the study of the outer solar system. PMID:11603399
The Impact of Nursing Students' Prior Chemistry Experience on Academic Performance and Perception of Relevance in a Health Science Course
ERIC Educational Resources Information Center
Boddey, Kerrie; de Berg, Kevin
Nursing students have typically found the study of chemistry to be one of their major challenges in a nursing course. This mixed method study was designed to explore how prior experiences in chemistry might impact chemistry achievement during a health science unit. Nursing students (N = 101) studying chemistry as part of a health science unit were…
Developments in Analytical Chemistry: Acoustically Levitated Drop Reactors for Enzyme Reaction Kinetics and Single-Walled Carbon Nanotube-Based Sensors for Detection of Toxic Organic Phosphonates
ERIC Educational Resources Information Center
Field, Christopher Ryan
Developments in analytical chemistry were made using acoustically levitated small volumes of liquid to study enzyme reaction kinetics and by detecting volatile organic compounds in the gas phase using single-walled carbon nanotubes. Experience gained in engineering, electronics, automation, and software development from the design and…
NMR Kinetics of the S[subscript N]2 Reaction between BuBr and I[superscript -]: An Introductory Organic Chemistry Laboratory Exercise
ERIC Educational Resources Information Center
Mobley, T. Andrew
A simple organic chemistry experiment is described that investigates the kinetics of the reaction between 1-bromobutane (BuBr) and iodide (I[superscript -]) as followed by observing the disappearance of BuBr and the appearance of 1-iodobutane (BuI) using [superscript 1]H NMR spectroscopy. In small groups of three to four, students acquire data to…
Imidazole as a pH Probe: An NMR Experiment for the General Chemistry Laboratory
ERIC Educational Resources Information Center
Hagan, William J., Jr.; Edie, Dennis L.; Cooley, Linda B.
The analysis describes an NMR experiment for the general chemistry laboratory, which employs an unknown imidazole solution to measure the pH values. The described mechanism can also be used for measuring the acidity within the isolated cells.
A Solid State Chemistry Experiment: Dislocations in Etched Calcite by Polaroid Photomicrography
ERIC Educational Resources Information Center
Agnew, N. H.
Suggests that adequate attention should be given to lattice imperfections in teaching solid state chemistry. Some concepts to be included in such a program are explained. An experiment to be performed by undergraduates on photomicrography is described in detail. (PS)
Bridging Native American Culture and Chemistry: Gas Chromatography Experiments That Examine Native Foods.
ERIC Educational Resources Information Center
Sykes, Andrew G.; Caple, Gerald
Describes three chemistry experiments that link common foodstuffs traditionally and currently harvested by Native Americans in different parts of North America to modern chemical instrumentation and discovery methods. (CCM)
From polymer to small organic molecules: a tight relationship between radical chemistry and solid-phase organic synthesis.
Mirizzi, Danilo; Pulici, Maurizio
Since Gomberg's discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest of organic chemists has shifted towards the application of usual "in-solution" radical chemistry to the solid-phase, ranging from the use of supported reagents for radical reactions, to the development of methodologies for the synthesis of small molecules or potential libraries. The aim of this review is to put in perspective radical chemistry, moving it away from its origin as a synthetic means for solid supports, to becoming a useful tool for the synthesis of small molecules. PMID:21512439
The Synthesis of 1-Phenyl-1,2,3,4-tetrahydroisoquinolines: An Undergraduate Organic Laboratory Experiment and Class Project.
ERIC Educational Resources Information Center
Letcher, R. M.; Sammes, M. P.
Describes an undergraduate organic chemistry experiment (requiring three/four 3-hour laboratory sessions) involving a four-stage synthesis of 1-phenyl-1,2,3,4-tetrahydroisoquinolines via the Pictet-Spengler route. In addition, the experiment allows students to study the spectra and properties of aklaloid-like materials while completing several…
Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 4, Organic methods
Not Available
This interim notice covers the following: extractable organic halides in solids, total organic halides, analysis by gas chromatography/Fourier transform-infrared spectroscopy, hexadecane extracts for volatile organic compounds, GC/MS analysis of VOCs, GC/MS analysis of methanol extracts of cryogenic vapor samples, screening of semivolatile organic extracts, GPC cleanup for semivolatiles, sample preparation for GC/MS for semi-VOCs, analysis for pesticides/PCBs by GC with electron capture detection, sample preparation for pesticides/PCBs in water and soil sediment, report preparation, Florisil column cleanup for pesticide/PCBs, silica gel and acid-base partition cleanup of samples for semi-VOCs, concentrate acid wash cleanup, carbon determination in solids using Coulometrics` CO{sub 2} coulometer, determination of total carbon/total organic carbon/total inorganic carbon in radioactive liquids/soils/sludges by hot persulfate method, analysis of solids for carbonates using Coulometrics` Model 5011 coulometer, and soxhlet extraction.
Looking beyond Lewis Structures: A General Chemistry Molecular Modeling Experiment Focusing on Physical Properties and Geometry
ERIC Educational Resources Information Center
Linenberger, Kimberly J.; Cole, Renee S.; Sarkar, Somnath
We present a guided-inquiry experiment using Spartan Student Version, ready to be adapted and implemented into a general chemistry laboratory course. The experiment provides students an experience with Spartan Molecular Modeling software while discovering the relationships between the structure and properties of molecules. Topics discussed within…
Photochemistry of Benzophenone in 2Propanol: An Easy Experiment for Undergraduate Physical Chemistry Courses
M. S. Churio; M. A. Grela
In this article we describe a laboratory experiment for undergraduate physical chemistry courses dealing with the photophysics and photochemistry of benzophenone in 2-propanol. This is an easy-to-perform experiment aimed to introduce the basic concepts of photochemistry which may help to achieve a systematic approach to the subject, incorporating related topics of chemical kinetics and molecular spectroscopy. This experiment provides quantitative
PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Entering the leinamycin rearrangement via 2-(trimethylsilyl)ethyl sulfoxides
Gates, Kent. S.
DNA is relevant to diverse fields including medicinal chemistry, toxicology, and biotechnology that mimics leinamycin (ref. 15). This journal is © The Royal Society of Chemistry 2007 Org. Biomol. ChemPAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Entering the leinamycin rearrangement via
Stereoisomerism in Coordination Chemistry: A Laboratory Experiment for Undergraduate Students.
ERIC Educational Resources Information Center
Gargallo, Maria Fe; And Others
Describes an experimental procedure to acquaint inorganic chemistry students with stereochemical concepts using tris-(2,3-butanediamine)cobalt(III). Notes two isomeric forms exist and both form metal chelates. Separation is accomplished by chromatography and analysis is by NMR and infrared spectroscopy. Provides spectra of isomers. (MVL)
Preparation of Gold Nanoparticles Using Tea: A Green Chemistry Experiment
ERIC Educational Resources Information Center
Sharma, R. K.; Gulati, Shikha; Mehta, Shilpa
Assimilating green chemistry principles in nanotechnology is a developing area of nanoscience research nowadays. Thus, there is a growing demand to develop environmentally friendly and sustainable methods for the synthesis of nanoparticles that utilize nontoxic chemicals, environmentally benign solvents, and renewable materials to avoid their…
Extending physical chemistry to populations of living organisms. First step: measuring coupling strength
Di, Zengru
For any system, whether physical or non-physical, knowledge of the form and strength of inter-individual interactions is a key-information. In an approach based on statistical physics one needs to know the interaction Hamiltonian. For non-physical systems, based on qualitative arguments similar to those used in physical chemistry, interaction strength gives useful clues about the macroscopic properties of the system. Even though our ultimate objective is the understanding of social phenomena, we found that systems composed of insects (or other living organisms) are of great convenience for investigating group effects. In this paper we show how to design experiments that enable us to estimate the strength of interaction in groups of insects. By repeating the same experiments with increasing numbers of insects, ranging from less than 10 to several hundreds, one is able to explore key-properties of the interaction. The data turn out to be consistent with a global correlation that is independent of distance (at l...
Chemistry and Applications of Metal-Organic Materials
Zhao, Dan
control. The postsynthetic modification via click reaction with azide-terminated polyethylene glycol turned them into metallomicelles, which showed controlled release of an anticancer drug 5-fluorouracil. In summary, two kinds of metal-organic materials...
Chemistry and Applications of Metal-Organic Materials
Zhao, Dan
control. The postsynthetic modification via click reaction with azide-terminated polyethylene glycol turned them into metallomicelles, which showed controlled release of an anticancer drug 5-fluorouracil. In summary, two kinds of metal-organic materials...
Art, Meet Chemistry; Chemistry, Meet Art: Case Studies, Current Literature, and Instrumental Methods Combined to Create a Hands-On Experience for Nonmajors and Instrumental Analysis Students
ERIC Educational Resources Information Center
Nivens, Delana A.; Padgett, Clifford W.; Chase, Jeffery M.; Verges, Katie J.; Jamieson, Deborah S.
Case studies and current literature are combined with spectroscopic analysis to provide a unique chemistry experience for art history students and to provide a unique inquiry-based laboratory experiment for analytical chemistry students. The XRF analysis method was used to demonstrate to nonscience majors (art history students) a powerful…
NSDL National Science Digital Library
K-12 Outreach,
Chemistry is the scientific study of matter and its interaction with other matter and with energy. It is the branch of natural science that deals with the composition of substances and their properties and reactions.
Application of the organic on water reactions to prebiotic chemistry
NASA Astrophysics Data System (ADS)
Kolb, Vera M.
The old view that prebiotic reactions in water are hampered by the low solubility of the organic compounds in water is now being revised due to the discoveries of the reactions "on water". These reactions occur in the heterogeneous system comprising of the organic compounds and water. Unexpectedly, such reactions are extremely efficient; they often give quantitative yields, and are accelerated in the presence of water as compared to the organic solvents. These "on water" reactions are not the same as the "in water" reactions, which occur in solution, and are thus homogenous. Examples of the "on water" reactions include Diels-Alder, Claisen, Passerini and Ugi reactions, among many others. Some of these reactions are multicomponent, but give a single product. We survey a selected number of the "on water" reactions, which have a potential prebiotic applications.
Emergence of Complex Chemistry on an Organic Monolayer.
Prins, Leonard J
In many origin-of-life scenarios, inorganic materials, such as FeS or mineral clays, play an important role owing to their ability to concentrate and select small organic molecules on their surface and facilitate their chemical transformations into new molecules. However, considering that life is made up of organic matter, at a certain stage during the evolution the role of the inorganic material must have been taken over by organic molecules. How this exactly happened is unclear, and, indeed, a big gap separates the rudimentary level of organization involving inorganic materials and the complex organization of cells, which are the building blocks of life. Over the past years, we have extensively studied the interaction of small molecules with monolayer-protected gold nanoparticles (Au NPs) for the purpose of developing innovative sensing and catalytic systems. During the course of these studies, we realized that the functional role of this system is very similar to that typically attributed to inorganic surfaces in the early stages of life, with the important being difference that the functional properties (molecular recognition, catalysis, signaling, adaptation) originate entirely from the organic monolayer rather than the inorganic support. This led us to the proposition that this system may serve as a model that illustrates how the important role of inorganic surfaces in dictating chemical processes in the early stages of life may have been taken over by organic matter. Here, we reframe our previously obtained results in the context of the origin-of-life question. The following functional roles of Au NPs will be discussed: the ability to concentrate small molecules and create different local populations, the ability to catalyze the chemical transformation of bound molecules, and, finally, the ability to install rudimentary signaling pathways and display primitive adaptive behavior. In particular, we will show that many of the functional properties of the system originate from two features: the presence of metal ions that are complexed in the organic monolayer and the multivalent nature of the system. Complexed metal ions play an important role in determining the affinity and selectivity of the interaction with small molecules, but serve also as regulatory elements for determining how many molecules are bound simultaneously. Importantly, neighboring metal ion complexes also create catalytic pockets in which two metal ions cooperatively catalyze the cleavage of an RNA-model compound. The multivalent nature of the system permits multiple noncovalent interactions with small molecules that enhances the affinity, but is also at the basis of simple signal transduction pathways and adaptive behavior. PMID:26098550
The Big Picture: A Classroom Activity for Organic Chemistry
ERIC Educational Resources Information Center
Poon, Thomas
The new approach used for exploring new ways of enhancing experiences for students and instructors in science class is described. A fun activity conducted in the workshop for the observation of evolvement of group dynamics is discussed.
Geochemistry and Organic Chemistry on the Surface of Titan
NASA Technical Reports Server (NTRS)
Lunine, J. I.; Beauchamp, P.; Beauchamp, J.; Dougherty, D.; Welch, C.; Raulin, F.; Shapiro, R.; Smith, M.
Titan's atmosphere produces a wealth of organic products from methane and nitrogen. These products, deposited on the surface in liquid and solid form, may interact with surface ices and energy sources to produce compounds of exobiological interest. Additional information is contained in the original extended abstract.
Culturing Reality: How Organic Chemistry Graduate Students Develop into Practitioners
ERIC Educational Resources Information Center
Bhattacharyya, Gautam; Bodner, George M.
Although one of the presumed aims of graduate training programs is to help students develop into practitioners of their chosen fields, very little is known about how this transition occurs. In the course of studying how graduate students learn to solve organic synthesis problems, we were able to identify some of the key factors in the epistemic…
Accidental Drowning or Foul Play?: A Case Study in Organic Chemistry
ERIC Educational Resources Information Center
Konaklieva, Monika
This case was developed for a sophomore organic chemistry lab to illustrate how a combination of techniques is usually required in the identification of chemical compounds. It involves a murder mystery with a forensic twist: Two bodies have been recovered from two different lakes, but because of a mix-up at the morgue, the coroner is unable to…
A New Higher Education Curriculum in Organic Chemistry: What Questions Should Be Asked?
ERIC Educational Resources Information Center
Lafarge, David L.; Morge, Ludovic M.; Méheut, Martine M.
Organic chemistry is often considered to be a difficult subject to teach and to learn, particularly as students prefer to resort to memorization alone rather than reasoning using models from chemical reactivity. Existing studies have led us to suggest principles for redefining the curriculum, ranging from its overall structure to the tasks given…
Emissions of volatile organic compounds from vegetation and the implications for atmospheric chemistry
Fred Fehsenfeld; Jack Calvert; Ray Fall; Paul Goldan; A. B. Guenther; C. N. Hewitt; Brian Lamb; Shaw Liu; Michael Trainer; Hal Westberg; Pat Zimmerman
Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between
Using Biocatalysis to Integrate Organic Chemistry into a Molecular Biology Laboratory Course
ERIC Educational Resources Information Center
Beers, Mande; Archer, Crystal; Feske, Brent D.; Mateer, Scott C.
Current cutting-edge biomedical investigation requires that the researcher have an operational understanding of several diverse disciplines. Biocatalysis is a field of science that operates at the crossroads of organic chemistry, biochemistry, microbiology, and molecular biology, and provides an excellent model for interdisciplinary research. We…
Using Green Chemistry Principles as a Framework to Incorporate Research into the Organic Laboratory Curriculum
ERIC Educational Resources Information Center
Lee, Nancy E.; Gurney, Rich; Soltzberg, Leonard
Despite the accepted pedagogical value of integrating research into the laboratory curriculum, this approach has not been widely adopted. The activation barrier to this change is high, especially in organic chemistry, where a large number of students are required to take this course, special glassware or setups may be needed, and dangerous…
2005 Nobel Prize in Chemistry: Development of the Olefin Metathesis Method in Organic Synthesis
ERIC Educational Resources Information Center
Casey, Charles P.
The 2005 Nobel Prize in Chemistry was awarded "for the development of the metathesis method in organic synthesis". The discoveries of the laureates provided a chemical reaction used daily in the chemical industry for the efficient and more environmentally friendly production of important pharmaceuticals, fuels, synthetic fibers, and many other…
PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Synthesis and evaluation of caged Garcinia xanthones
Theodorakis, Emmanuel
PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Synthesis and evaluation of caged Garcinia and potent bioactivities exhibited by several family members of the caged Garcinia xanthones, we developed pharmacophore. Introduction The Garcinia genus of tropical plants has yielded a structurally intriguing family
The Flipped Classroom for Teaching Organic Chemistry in Small Classes: Is It Effective?
ERIC Educational Resources Information Center
Fautch, Jessica M.
The flipped classroom is a pedagogical approach that moves course content from the classroom to homework, and uses class time for engaging activities and instructor-guided problem solving. The course content in a sophomore level Organic Chemistry I course was assigned as homework using video lectures, followed by a short online quiz. In class,…
A Performance Enhanced Interactive Learning Workshop Model as a Supplement for Organic Chemistry Instruction
ERIC Educational Resources Information Center
Phillips, Karen E. S.; Grose-Fifer, Jilliam
In this study, the authors describe a Performance Enhanced Interactive Learning (PEIL) workshop model as a supplement for organic chemistry instruction. This workshop model differs from many others in that it includes public presentations by students and other whole-class-discussion components that have not been thoroughly investigated in the…
Using Web-Based Video as an Assessment Tool for Student Performance in Organic Chemistry
ERIC Educational Resources Information Center
Tierney, John; Bodek, Matthew; Fredricks, Susan; Dudkin, Elizabeth; Kistler, Kurt
This article shows the potential for using video responses to specific questions as part of the assessment process in an organic chemistry class. These exercises have been used with a postbaccalaureate cohort of 40 students, learning in an online environment, over a period of four years. A second cohort of 25 second-year students taking the…
Sustaining Change in Upper Level Courses: Peer-Led Workshops in Organic Chemistry and Biochemistry
ERIC Educational Resources Information Center
Platt, Terry; Roth, Vicki; Kampmeier, Jack A.
Our peer-led collaborative learning groups, called Workshops, have now had extended success in two upper-level courses in chemistry and biochemistry. These Workshops are in turn supported by a third upper-level course for training peer-leaders. Our data confirm that the initial positive results from the introduction of Workshops in organic…
Vegetation effects on soil organic matter chemistry of aggregate fractions in a Hawaiian forest
Technology Transfer Automated Retrieval System (TEKTRAN)
We examined chemical changes from live plant tissue to soil organic matter (SOM) to determine the persistence of individual plant compounds into soil aggregate fractions. We characterized the tissue chemistry of a slow- (Dicranopteris linearis) and fast-decomposing species (Cheirodendron trigynum) a...
The Impacts of an "Organic First" Chemistry Curriculum at a Liberal Arts College
ERIC Educational Resources Information Center
Malinak, Steven M.; Bayline, Jennifer Logan; Brletic, Patricia A.; Harris, Mark F.; Iuliucci, Robbie J.; Leonard, Michael S.; Matsuno, Nobunaka; Pallack, Linda A.; Stringfield, Thomas W.; Sunderland, Deborah Polvani
The chemistry department at Washington & Jefferson College implemented an "organic first" curriculum in the fall semester of 2005. Assessment data suggest that the net impact of this change for the department and associated constituencies has been positive: (i) Student outcomes have generally not been impacted by the curricular…
Case Study Using Online Homework in Undergraduate Organic Chemistry: Results and Student Attitudes
ERIC Educational Resources Information Center
Parker, Laurie L.; Loudon, G. Marc
Managing student needs for effective learning in a large-enrollment, introductory organic chemistry course can be a challenging task. Because instructor time is at a premium, it is imperative to find resources that engage the students in active learning and provide them with feedback about their understanding of course content. Appropriately…
An Introductory Organic Chemistry Review Homework Exercise: Deriving Potential Mechanisms for Glucose Ring Opening in Mutarotation
ERIC Educational Resources Information Center
Murdock, Margaret; Holman, R. W.; Slade, Tyler; Clark, Shelley L. D.; Rodnick, Kenneth J.
A unique homework assignment has been designed as a review exercise to be implemented near the end of the one-year undergraduate organic chemistry sequence. Within the framework of the exercise, students derive potential mechanisms for glucose ring opening in the aqueous mutarotation process. In this endeavor, 21 general review principles are…
Microwave-Assisted Chemistry: Synthetic Applications for Rapid Assembly of Nanomaterials and Organics
The magic of microwave (MW) heating technique, termed as the Bunsen burner of the 21th Century, has emerged as valuable alternative in synthesis of organics, polymers, inorganics, and nanomaterials. Important innovations in MW-assisted chemistry now enable chemists to prepare cat...
Assessment of Organic Chemistry Students' Knowledge of Resonance-Related Structures
ERIC Educational Resources Information Center
Betancourt-Perez, Rosa; Olivera, Luis Javier; Rodriguez, Julio E.
This study examines how well second-year nonmajor organic chemistry students are learning to draw, interpret, and understand resonance-related structures. Students were tested seven times throughout an academic year using a set of four tasks that reflected their understanding of what these structures represent and how they relate to each other.…
Students' Understanding of the Descriptive and Predictive Nature of Teaching Models in Organic Chemistry
ERIC Educational Resources Information Center
Treagust, David F.; Chittleborough, Gail D.; Mamiala, Thapelo L.
The purpose of the study was to investigate secondary students' understanding of the descriptive and predictive nature of teaching models used in representing compounds in introductory organic chemistry. Of interest were the relationships between teaching models, scientific models, and students' mental models and expressed models. The results from…
What Lies at the Heart of Good Undergraduate Teaching? A Case Study in Organic Chemistry
ERIC Educational Resources Information Center
Davidowitz, Bette; Rollnick, Marissa
Teaching organic chemistry at the undergraduate level has long been regarded as challenging and students are often alienated by the mass of detail which seems to characterise the subject. In this paper we investigate the practice of an accomplished lecturer by trying to capture and portray his pedagogical content knowledge, PCK, in order to reveal…
Decorating with Arrows: Toward the Development of Representational Competence in Organic Chemistry
ERIC Educational Resources Information Center
Grove, Nathaniel P.; Cooper, Melanie M.; Rush, Kelli M.
Much effort has been expended in developing improved methods for presenting mechanistic thinking and the curved-arrow notation to organic chemistry students; however, most of these techniques are not research-based. The little research that has been conducted has mainly focused on understanding the meaning that students associate with the…
Adapting to Student Learning Styles: Engaging Students with Cell Phone Technology in Organic Chemistry Instruction
ERIC Educational Resources Information Center
Pursell, David P.
Students of organic chemistry traditionally make 3 x 5 in. flash cards to assist learning nomenclature, structures, and reactions. Advances in educational technology have enabled flash cards to be viewed on computers, offering an endless array of drilling and feedback for students. The current generation of students is less inclined to use…
Integrated Concentration in Science, 2012 Sugar an Organic Chemistry Lesson Plan
Auerbach, Scott M.
© Integrated Concentration in Science, 2012 Sugar an Organic Chemistry Lesson Plan Objective is sugar? A carbohydrate. Explain importance of carbohydrates as biomolecules (starch, cellulose, sugars sugar in fruits, Mono. Rxns - -OH groups can convert to esters and ethers, making molecule easier
A Survey of the Practices, Procedures, and Techniques in Undergraduate Organic Chemistry Teaching Laboratories
ERIC Educational Resources Information Center
Martin, Christopher B.; Schmidt, Monica; Soniat, Michael
A survey was conducted of four-year institutions that teach undergraduate organic chemistry laboratories in the United States. The data include results from over 130 schools, describes the current practices at these institutions, and discusses the statistical results such as the scale of the laboratories performed, the chemical techniques applied,…
Page 1 of 4 ORGANIC CHEMISTRY CAS CH203 Lecture Section AA
Porco Jr., John A.
SCI 113 Wed 4:00- 5:00 pm Lecture Textbooks and Other Course Material.: (1) Organic Chemistry 7th) and a final examination (2 h). If the median grade of an examination is less than 75%, the median grade will be raised to a 75% by adding a constant amount (not more than 20%, however) to the grade of each student
Structure and Evaluation of Flipped Chemistry Courses: Organic & Spectroscopy, Large and Small, First to Third Year, English and French
ERIC Educational Resources Information Center
Flynn, Alison B.
Organic chemistry is a traditionally difficult subject with high failure & withdrawal rates and many areas of conceptual difficulty for students. To promote student learning and success, four undergraduate organic chemistry and spectroscopy courses at the first to third year level (17-420 students) were "flipped" in 2013-2014. In the…
Using Commercially Available Techniques to Make Organic Chemistry Representations Tactile and More Accessible to Students with Blindness or Low Vision
ERIC Educational Resources Information Center
Supalo, Cary A.; Kennedy, Sean H.
Organic chemistry courses can present major obstacles to access for students with blindness or low vision (BLV). In recent years, efforts have been made to represent organic chemistry concepts in tactile forms for blind students. These methodologies are described in this manuscript. Further work being done at Illinois State University is also…
Perry's Scheme of Intellectual and Epistemological Development as a Framework for Describing Student Difficulties in Learning Organic Chemistry
ERIC Educational Resources Information Center
Grove, Nathaniel P.; Bretz, Stacey Lowery
We have investigated student difficulties with the learning of organic chemistry. Using Perry's Model of Intellectual Development as a framework revealed that organic chemistry students who function as dualistic thinkers struggle with the complexity of the subject matter. Understanding substitution/elimination reactions and multi-step syntheses is…
Using Tactile Learning Aids for Students with Visual Impairments in a First-Semester Organic Chemistry Course
ERIC Educational Resources Information Center
Poon, Thomas; Ovadia, Ronit
This paper describes two techniques for rendering visual concepts encountered in an organic chemistry course into tactile representations for students who have low vision. The techniques--which utilize commercially available products--facilitate communication of organic chemistry between student and instructor. (Contains 1 figure, 2 tables and 1…
The Impacts of Marine Organic Emissions on Atmospheric Chemistry and Climate (Invited)
NASA Astrophysics Data System (ADS)
Meskhidze, N.; Gantt, B.
Using laboratory studies and global/regional climate model results, this talk will contribute to two main research questions: 1) what can be learned about the carbon emission inducing stress factors for marine algae, and 2) what is a potential impact of marine biogenic volatile organic compound (VOC) emissions on global atmospheric chemistry and climate. Marine photosynthetic organisms emit VOCs which can form secondary organic aerosols (SOA). Currently large uncertainty exists in the magnitude of the marine biogenic sources, their spatiotemporal distribution, controlling factors, and contributions to natural background of organic aerosols. Here laboratory results for the production of isoprene and four monoterpene (?-pinene, ?-pinene, camphene and d-limonene) compounds as a function of variable light and temperature regimes for 6 different phytoplankton species will be discussed. The experiment was designed to simulate the regions where phytoplankton is subjected to changeable light/temperature conditions. The samples were grown and maintained at a climate controlled room. VOCs accumulated in the water and headspace above the water were measured by passing the sample through a gas chromatography/mass system equipped with a sample pre-concentrator allowing detection of low ppt levels of hydrocarbons. The VOC production rates were distinctly different for light/temperature stressed (the first 12 hour cycle at light/temperature levels higher than what the cultures were acclimated to in a climate controlled room) and photo/temperature-acclimated (the second 12 hour light/temperature cycle) states. In general, all phytoplankton species showed a rapid increase in isoprene and monoterpene production at higher light levels (between 150 to 420 ?E m-2 s-1) until a constant production rate was reached. Isoprene and ?-pinene, production rates also increased with temperature until a certain level, after which the rates declined as temperature increased further. Two modeling studies with the online emissions of marine isoprene/monoterpene and size-resolved marine primary organic aerosol have been carried out. The US EPA regional-scale Community Multiscale Air Quality modeling system was used to determine the impact of marine emissions on air quality, while the global-through-urban WRF/Chem model was applied to examine effect of ocean-derived trace gases and aerosols on chemistry-aerosol-cloud-climate interactions. With the isoprene reactions included in this study, the average contribution of marine isoprene to SOA and ozone (O3) concentrations is predicted to be small, up to 0.004 ?g m-3 for SOA and 0.2 ppb for O3 in coastal urban areas. When marine primary organic emissions are included, PM2.5 levels can be increased by 0.1-0.3 ?g m-3 (up to 5%) in some coastal cities such as San Francisco, CA. Regionally, marine organics (primary and secondary) can cause up to 20% increase in surface cloud condensation nuclei concentration. Global effects on cloud droplet number and indirect forcing are predicted to be small, less than 1 cm-3 and -0.1 W m-2, respectively.
Bromine Chemistry in the Tropical UTLS during the 2011, 2013 and 2014 ATTREX Experiments
NASA Astrophysics Data System (ADS)
Werner, Bodo; Stutz, Jochen; Spolaor, Max; Festa, James; Tsai, Catalina; Colosimo, Fedele; Cheung, Ross; Deutschmann, Tim; Raecke, Rasmus; Scalone, Lisa; Tricoli, Ugo; Pfeilsticker, Klaus; Navarro, Maria; Atlas, Elliot; Chipperfield, Martyn; Hossaini, Ryan
Bromine plays an important role for the chemistry of ozone in the stratosphere and upper troposphere. An accurate quantitative understanding of the sources, sinks, and chemical transformation of bromine species is thus important to understand the bromine budget in the upper troposphere and lower stratosphere (UTLS), which also serves as a gate to the stratosphere. Vertical transport of very short-lived organic bromine precursors and inorganic product gases has been identified as the main source of bromine in the UTLS. However, the contribution of inorganic vs. organic compounds is not well quantified, particularly in the tropical UTLS. A limb scanning Differential Optical Absorption Spectroscopy instrument was deployed onboard NASA's UAV Global Hawk during the NASA Airborne Tropical TRopopause EXperiment (ATTREX) during a series of flights into the eastern and western Pacific tropopause layer (flight altitudes up to 18 km), which is a gateway to the stratosphere. The measurement methodology to retrieve vertical trace gas concentration profiles will be briefly presented. Observations of BrO, NO2 and O3 and of other trace species, in particular of brominated hydrocarbons are compared with simulations of the SLIMCAT CTM and interpreted with respect to photochemistry and the budget of bromine within the tropical tropopause layer (TTL).
Organic Chemistry: From the Interstellar Medium to the Solar System
NASA Technical Reports Server (NTRS)
Sandford, Scott; Witteborn, Fred C. (Technical Monitor)
This talk will review the various types of organic materials observed in different environments in the interstellar medium, discuss the processes by which these materials may have formed and been modified, and present the evidence supporting the contention that at least a fraction of this material survived incorporation, substantially unaltered, into our Solar System during its formation. The nature of this organic material is of direct interest to issues associated with the origin of life, both because this material represents a large fraction of the Solar System inventory of the biogenically-important elements, and because many of the compounds in this inventory have biogenic implications. Several specific examples of such molecules will be briefly discussed.
Primordial organic chemistry and the origin of life.
NASA Technical Reports Server (NTRS)
Ponnamperuma, C.
Aspects of Darwinian revolution are discussed together with spontaneous generation, the inorganic chemical evolution, the primitive atmosphere, and interstellar matter. The significance of the change of the earth's reducing atmosphere to an atmosphere with oxidizing characteristics is considered. Experiments regarding the abiogenic synthesis of nucleic acids and proteins are reported. It was found that micromolecules can be formed in simulation experiments. The condensation reaction taking place in the presence of water was studied together with the condensation reaction taking place in the relative absence of water or under hypohydrous conditions. Jupiter simulation studies were conducted, and lunar and meteorite material was analyzed.
PERSPECTIVE: From computational quantum chemistry to computational biology: experiments and computations are (full) partners
Buyong Ma; Ruth Nussinov
Computations are being integrated into biological research at an increasingly fast pace. This has not only changed the way in which biological information is managed; it has also changed the way in which experiments are planned in order to obtain information from nature. Can experiments and computations be full partners? Computational chemistry has expanded over the years, proceeding from computations
An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques
ERIC Educational Resources Information Center
Duxbury, Mark
An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…
Size Exclusion Chromatography: An Experiment for High School and Community College Chemistry and Biotechnology Laboratory Programs
ERIC Educational Resources Information Center
Brunauer, Linda S.; Davis, Kathryn K.
A simple multiday laboratory exercise suitable for use in a high school or community college chemistry course or a biotechnology advanced placement biology course is described. In this experiment students gain experience in the use of column chromatography as a tool for the separation and characterization of biomolecules, thus expanding their…
Thai Undergraduate Chemistry Practical Learning Experiences Using the Jigsaw IV Method
ERIC Educational Resources Information Center
Jansoon, Ninna; Somsook, Ekasith; Coll, Richard K.
The research reported in this study consisted of an investigation of student learning experiences in Thai chemistry laboratories using the Jigsaw IV method. A hands-on experiment based on the Jigsaw IV method using a real life example based on green tea beverage was designed to improve student affective variables for studying topics related to…
Annotated List of Chemistry Laboratory Experiments with Computer Access. Final Report.
ERIC Educational Resources Information Center
Bunce, S. C.; And Others
Project Chemlab was designed to prepare an "Annotated List of Laboratory Experiments in Chemistry from the Journal of Chemical Education (1957-1979)" and to develop a computer file and program to search for specific types of experiments. Provided in this document are listings (photoreduced copies of printouts) of over 1500 entries classified into…
Thermodynamic Exploration of Eosin-Lysozyme Binding: A Physical Chemistry and Biochemistry Laboratory Experiment
ERIC Educational Resources Information Center
Huisman, Andrew J.; Hartsell, Lydia R.; Krueger, Brent P.; Pikaart, Michael J.
We developed a modular pair of experiments for use in the undergraduate physical chemistry and biochemistry laboratories. Both experiments examine the thermodynamics of the binding of a small molecule, eosin Y, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In…
GC-MS Analysis of [gamma]-Hydroxybutyric Acid Analogs: A Forensic Chemistry Experiment
ERIC Educational Resources Information Center
Henck, Colin; Nally, Luke
An upper-division forensic chemistry experiment is described. It involves using glycolic acid and sodium glycolate as analogs of [gamma]-hydroxybutyric acid and its sodium salt. The experiment shows the use of silylation in GC-MS analysis and gives students the opportunity to work with a commonly used silylating reagent,…
Topics in Chemical Instrumentation: XCVIII. Experiments Involving Thermal Methods of Analysis for Undergraduate Chemistry Laboratories.
ERIC Educational Resources Information Center
Ewing, Galen W., Ed.
Explains some experiments involving thermal methods of analysis for undergraduate chemistry laboratories. Some experiments are: (1) the determination of the density and degree of crystallinity of a polymer; and (2) the determination of the specific heat of a nonvolatile compound. (HM)
Creative Report Writing in Undergraduate Organic Chemistry Laboratory Inspires Nonmajors
ERIC Educational Resources Information Center
Henary, Maged; Owens, Eric A.; Tawney, Joseph G.
Laboratory-based courses require students to compose reports based on the performed experiments to assess their overall understanding of the presented material; unfortunately, the sterile and formulated nature of the laboratory report disinterests most students. As a result, the outcome is a lower-quality product that does not reveal full…
Simons, Jack
there to find announcements from your TA and to view your lab grades. You may also email your labmates or your, an understanding of the theory behind the lab experiments, and the writing of scientific reports with correct Published by HaydenMcNeil, ©2013. ISBN: 9780738053363 Lab Notebook (REQUIRED) Customized Lab Record
Variability of the carbonate chemistry in a shallow, seagrass-dominated ecosystem: implications for ocean acidification experiments
Challenger, Roberta; Robbins, Lisa L.; Mcclintock, James B.
Open ocean observations have shown that increasing levels of anthropogenically derived atmospheric CO2 are causing acidification of the world's oceans. Yet little is known about coastal acidification and studies are just beginning to characterise the carbonate chemistry of shallow, nearshore zones where many ecologically and economically important organisms occur. We characterised the carbonate chemistry of seawater within an area dominated by seagrass beds (Saint Joseph Bay, Florida) to determine the extent of variation in pH and pCO2 over monthly and daily timescales. Distinct diel and seasonal fluctuations were observed at daily and monthly timescales respectively, indicating the influence of photosynthetic and respiratory processes on the local carbonate chemistry. Over the course of a year, the range in monthly values of pH (7.36-8.28), aragonite saturation state (0.65-5.63), and calculated pCO2 (195-2537 ?atm) were significant. When sampled on a daily basis the range in pH (7.70-8.06), aragonite saturation state (1.86-3.85), and calculated pCO2 (379-1019 ?atm) also exhibited significant range and indicated variation between timescales. The results of this study have significant implications for the design of ocean acidification experiments where nearshore species are utilised and indicate that coastal species are experiencing far greater fluctuations in carbonate chemistry than previously thought.
The surface chemistry of metal-organic frameworks.
McGuire, Christina V; Forgan, Ross S
Metal-organic frameworks (MOFs) have received particular attention over the last 20 years as a result of their attractive properties offering potential applications in a number of areas. Typically, these characteristics are tuned by functionalisation of the bulk of the MOF material itself. This Feature Article focuses instead on modification of MOF particles at their surfaces only, which can also offer control over the bulk properties of the material. The differing surface modification techniques available to the synthetic chemist will be discussed, with a focus on the effect of surface modification of MOFs on their fundamental properties and application in adsorption, catalysis, drug delivery and other areas. PMID:25116412
Water and Organics: A Lens to View the Coupled Physics and Chemistry of Protoplanetary Disks
NASA Astrophysics Data System (ADS)
Bergin, Edwin
We propose to study the formation and survival of water and organics in the terrestrial planet-forming zone of protoplanetary disks. The recent detections of these molecules in the warm, inner regions of classical T Tauri systems suggests that they can not only survive in a hostile radiation-dominated environment, but do so in great quantities. These observations have direct implications for the origins of terrestrial prebiotic material. Despite this apparent ubiquity, they appear absent in disks with inner gaps - the transitional disks - hypothesized to be systems containing young planetary systems. Thus, the abundance of gas phase water and organics possibly represents an important tracer of incipient planet-formation. The surprisingly large quantities of water observed can be explained by a previously unrecognised self-shielding mechanism in which water protects itself from the harmful effects of stellar radiation. At the same time the emergent water is theorized to provide a sanctuary for organic chemistry, thus explaining the correlation between the detections of water and organics. Furthermore, the absorption of starlight by water instead of dust also has profound - and as yet, unexplored - thermodynamic implications for the inner disk. Combining our observational and modeling strengths we shall perform a comprehensive study of the physical conditions that allow these molecules to exist. The proposed study emphasizes the inclusion of new physics, and as such is unique amongst theoretical models of disk physics and chemistry. This three stage program will first develop a thermodynamic model of gas in the inner disk that includes the thermodynamic implications of high concentrations of water. Second, organic chemistry networks will be developed that include high-temperature reactions and grain processes appropriate for the warm terrestrial zone. Finally, the water and organic chemistry will be solved in a suite of 2D disk models that include self- consistent treatments of thermodynamics, radiative transfer and chemistry. The models will be used to explore a large space of physical parameters that includes the development of transition systems. Our goals are to understand the conditions required for water and organic formation, the mechanisms by which they may form, and their relationship to one another. The ultimate product of the models will be observable predictions that can not only be compared to current data from NASA's Spitzer space mission, but also Herschel observations and future missions such as NASA's James Webb Space Telescope. These results will broaden our understanding of the chemistry in the natal habitable zone, and have direct relevance to NASA and the Origins of Solar Systems program, specifically Strategic Goal 3: Sub-goal 3C Advance scientic knowledge of the origin and history of the solar system and the potential for life elsewhere.
Flow through reactors for organic chemistry: directly electrically heated tubular mini reactors as an enabling technology for organic synthesis.
Kunz, Ulrich; Turek, Thomas
Until recently traditional heating in organic chemistry has been done with oil heating baths or using electric heat exchangers. With the advent of microwave equipment, heating by microwaves was rapidly introduced as standard method in organic chemistry laboratories, mainly because of the convenient possibility to operate at high temperature accompanied by accelerated reaction rates. In the present contribution we discuss the method of heating small, continuously operated reactors by passing electric current directly through the reactor wall as an enabling technology in organic chemistry. The benefit of this method is that the heat is generated directly inside the reactor wall. By this means high heating rates comparable to microwave ovens can be reached but at much lower cost for the equipment. A tool for the comparison of microwave heating and traditional heating is provided. As an example kinetic data for the acid catalyzed hydrolysis of methyl formate were measured using this heating concept. The reaction is not only a suitable model but also one of industrial importance since this is the main production process for formic acid. PMID:20300506
UAF LIVE Leadership Involvement and Volunteer Experience UAF Student Organization
Wagner, Diane
UAF LIVE Leadership Involvement and Volunteer Experience UAF Student Organization Advisor Handbook Organization UAF LIVE Program Student Organizations Phone: 907-474-1959 Fax: 907-474-5508 E-mail: fystuorg.....................................10 #12;3 Dear UAF Student Organization Advisors, On behalf of the UAF LIVE program, thank you for all
Organic chemistry of Murchison meteorite: Carbon isotopic fractionation
NASA Technical Reports Server (NTRS)
Yuen, G. U.; Blair, N. E.; Desmarais, D. J.; Cronin, J. R.; Chang, S.
The carbon isotopic composition of individual organic compounds of meteoritic origin remains unknown, as most reported carbon isotopic ratios are for bulk carbon or solvent extractable fractions. The researchers managed to determine the carbon isotopic ratios for individual hydrocarbons and monocarboxylic acids isolated from a Murchison sample by a freeze-thaw-ultrasonication technique. The abundances of monocarboxylic acids and saturated hydrocarbons decreased with increasing carbon number and the acids are more abundant than the hydrocarbon with the same carbon number. For both classes of compounds, the C-13 to C-12 ratios decreased with increasing carbon number in a roughly parallel manner, and each carboxylic acid exhibits a higher isotopic number than the hydrocarbon containing the same number of carbon atoms. These trends are consistent with a kinetically controlled synthesis of higher homologues for lower ones.
Tholins - Organic chemistry of interstellar grains and gas
NASA Technical Reports Server (NTRS)
Sagan, C.; Khare, B. N.
The paper discusses tholins, defined as complex organic solids formed by the interaction of energy - for example, UV light or spark discharge - with various mixtures of cosmically abundant gases - CH4, C2H6, NH3, H2O, HCHO, and H2S. It is suggested that tholins occur in the interstellar medium and are responsible for some of the properties of the interstellar grains and gas. Additional occurrences of tholins are considered. Tholins have been produced experimentally; 50 or so pyrolytic fragments of the brown, sometimes sticky substances have been identified by gas chromatography-mass spectrometry, and the incidence of these fragments in tholins produced by different procedures is reported.
Green, Enzymatic Syntheses of Divanillin and Diapocynin for the Organic, Biochemistry, or Advanced General Chemistry Laboratory
ERIC Educational Resources Information Center
Nishimura, Rachel T.; Giammanco, Chiara H.; Vosburg, David A.
Environmentally benign chemistry is an increasingly important topic both in the classroom and the laboratory. In this experiment, students synthesize divanillin from vanillin or diapocynin from apocynin, using horseradish peroxidase and hydrogen peroxide in water. The dimerized products form rapidly at ambient temperature and are isolated by…
UCLA CHEMISTRY-MATERIALS SCIENCE ORGANIC CONCENTRATION 2012-2013 CHEMISTRY-MATERIALS SCIENCE MAJOR (B.S.), ORGANIC CONCENTRATION: This concentration is designed primarily
Levine, Alex J.
A Physical Chemistry: Chemical Thermo Chem 20B; Math 32A or 3C; Physics 1A, 1B, 1C* 110B Physical Chemistry: Intro to Statistical Mechanics and Kinetics Chem 110A, 113A; Math 32B 113A Physical Chemistry C113B Physical Chemistry: Intro to Molecular Spectroscopy Chem 113A 114 (H) Physical Chemistry Lab
Computer Programs for Chemistry Experiments I and II.
ERIC Educational Resources Information Center
Reynard, Dale C.
This unit of instruction includes nine laboratory experiments. All of the experiments are from the D.C. Health Revision of the Chemical Education Materials Study (CHEMS) with one exception. Program six is the lab from the original version of the CHEMS program. Each program consists of three parts (1) the lab and computer hints, (2) the description…
A Study of the Liquid-Liquid Partitioning Process Using Reverse-Phase Liquid Chromatography: An Undergraduate Analytical Chemistry Experiment.
ERIC Educational Resources Information Center
Lochmuller, C. H.; And Others
Presents an undergraduate analytical chemistry experiment that promotes an interpretation of the molecular aspects of solute partitioning, enhancing student understanding of separation science and liquid chromatography. (CS)
A Ten-Year Experiment With Chemistry Students
ERIC Educational Resources Information Center
Meszaros, L.
Describes a polytechnical club" where college students must manually make laboratory equipment for experiments. Also introduces an evaluation procedure based on the student's intelligence and ability to work with others. (DS)
50-Minute Experiment: Soil Analysis for High School Chemistry Students.
ERIC Educational Resources Information Center
Baruch, Gerard, Ed.; And Others
Lists equipment and materials needed and procedures for analyzing soil, in which secondary school students experience practical applications to acid-base reactions, pH, oxidation-reduction, precipitation and solubility. (CS)
Chemistry Graduate Teaching Assistants' Experiences in Academic Laboratories and Development of a Teaching Self-image
NASA Astrophysics Data System (ADS)
Gatlin, Todd Adam
Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching. This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each study. First, phenomenological analysis was used to explore GTAs' experiences in an expository laboratory program. Post-teaching interviews were the primary data source. GTAs experiences were described in three dimensions: doing, knowing, and transferring. Gains available to GTAs revolved around general teaching skills. However, no gains specifically related to scientific development were found in this laboratory format. Case-study methods were used to explore and illustrate ways GTAs develop a GTA self-image---the way they see themselves as instructors. Two general chemistry laboratory programs that represent two very different instructional frameworks were chosen for the context of this study. The first program used a cooperative project-based approach. The second program used weekly, verification-type activities. End of the semester interviews were collected and served as the primary data source. A follow-up case study of a new cohort of GTAs in the cooperative problem-based laboratory was undertaken to investigate changes in GTAs' self-images over the course of one semester. Pre-semester and post-semester interviews served as the primary data source. Findings suggest that GTAs' construction of their self-image is shaped through the interaction of 1) prior experiences, 2) training, 3) beliefs about the nature of knowledge, 4) beliefs about the nature of laboratory work, and 5) involvement in the laboratory setting. Further GTAs' self-images are malleable and susceptible to change through their laboratory teaching experiences. Overall, this dissertation contributes to chemistry education by providing a model useful for exploring GTAs' development of a self-image in laboratory teaching. This work may assist laboratory instructors and coordinators in reconsidering, when applicable, GTA training and support. This work also holds considerable implications for how teaching experiences are conceptualized as part of the chemistry graduate education experience. Findings suggest that appropriate teaching experiences may contribute towards better preparing graduate students for their journey in becoming scientists.
Planetary and Space Science 55 (2007) 383400 The ORGANICS experiment on BIOPAN V: UV and space exposure
) on the EXPOSE facility on the International Space Station (ISS). For the small fluence that was collected during; International Space Station; Photo-stability 1. Introduction Carbon chemistry in space occurs most efficientlyPlanetary and Space Science 55 (2007) 383400 The ORGANICS experiment on BIOPAN V: UV and space
Emissions of volatile organic compounds from vegetation and the implications for atmospheric chemistry
Fehsenfeld, F.; Trainer, M. (National Oceanic and Atmospheric Administration, Boulder, CO (United States) Univ. of Colorado, Boulder (United States)); Calvert, J.; Guenther, A.B.; Zimmerman, P. (National Center for Atmospheric Research, Boulder, CO (United States)); Fall, R. (Univ. of Colorado, Boulder (United States)); Goldan, P.; Liu, S. (National Oceanic and Atmospheric Administration, Boulder, CO (United States)); Hewitt, C.N. (Lancaster Univ. (United Kingdom)); Lamb, B.; Westberg, H. (Washington State Univ., Pullman (United States))
Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between approximately 500 and 825 Tg yr[sup -1]. The volatile olefinic compounds, such as isoprene and the monoterpenes, are thought to constitute the bulk of these emissions. However, it is becoming increasingly clear that a variety of partially oxidized hydrocarbons, principally alcohols, are also emitted. The available information concerning the terrestrial vegetation as sources of volatile organic compounds is reviewed. The biochemical processes associated with these emissions of the compounds and the atmospheric chemistry of the emitted compounds are discussed. 197 refs., 25 figs., 7 tabs.
Emissions of volatile organic compounds from vegetation and the implications for atmospheric chemistry
NASA Astrophysics Data System (ADS)
Fehsenfeld, Fred; Calvert, Jack; Fall, Ray; Goldan, Paul; Guenther, Alex B.; Hewitt, C. Nicholas; Lamb, Brian; Liu, Shaw; Trainer, Michael; Westberg, Hal; Zimmerman, Pat
Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between approximately 500 and 825 Tg yr-1. The volatile olefinic compounds, such as isoprene and the monoterpenes, are thought to constitute the bulk of these emissions. However, it is becoming increasingly clear that a variety of partially oxidized hydrocarbons, principally alcohols, are also emitted. The available information concerning the terrestrial vegetation as sources of volatile organic compounds is reviewed. The biochemical processes associated with these emissions of the compounds and the atmospheric chemistry of the emitted compounds are discussed.
Laser-Induced Molecular Fluorescence: A Physical Chemistry Experiment.
ERIC Educational Resources Information Center
Tellinghuisen, Joel
Describes a companion experiment to the experimental study of the di-iodide visible absorption spectrum. Experimental details, interpretation, and data analysis are provided for an analysis of the di-iodide fluorescence excited by a visible laser, using a Raman instrument. (CS)
Laboratory Studies of the Reactive Chemistry and Changing CCN Properties of Secondary Organic Aerosol, Including Model Development
Scot Martin
The chemical evolution of secondary-organic-aerosol (SOA) particles and how this evolution alters their cloud-nucleating properties were studied. Simplified forms of full Koehler theory were targeted, specifically forms that contain only those aspects essential to describing the laboratory observations, because of the requirement to minimize computational burden for use in integrated climate and chemistry models. The associated data analysis and interpretation have therefore focused on model development in the framework of modified kappa-Koehler theory. Kappa is a single parameter describing effective hygroscopicity, grouping together several separate physicochemical parameters (e.g., molar volume, surface tension, and van't Hoff factor) that otherwise must be tracked and evaluated in an iterative full-Koehler equation in a large-scale model. A major finding of the project was that secondary organic materials produced by the oxidation of a range of biogenic volatile organic compounds for diverse conditions have kappa values bracketed in the range of 0.10 +/- 0.05. In these same experiments, somewhat incongruently there was significant chemical variation in the secondary organic material, especially oxidation state, as was indicated by changes in the particle mass spectra. Taken together, these findings then support the use of kappa as a simplified yet accurate general parameter to represent the CCN activation of secondary organic material in large-scale atmospheric and climate models, thereby greatly reducing the computational burden while simultaneously including the most recent mechanistic findings of laboratory studies.
Grade/Performance Contracts, Enhanced Communication, Cooperative Learning and Student Performance in Undergraduate Organic Chemistry
NASA Astrophysics Data System (ADS)
Dougherty, Ralph C.
This paper describes a grade/study-performance contract that was designed to increase student retention while maintaining academic performance levels in undergraduate organic chemistry. The experimental course included enhanced communication using electronic mail, and cooperative learning in addition to grade/study-performance contracts. The objective of the grade/study-performance contract was the development of learning skills with creation of a basis for unobtrusive auditing of performance. The retention rate in the experimental course was 0.82 for the first term and 0.93 for the second term. The overall retention was 0.76. This value was 3.8 times the average retention for the same sequence in the previous five years at the same institution. It was seven standard deviations away from the previous mean. The ACS Organic Chemistry Examination percentile score for the control section was 46+25 (n=117). The corresponding data for the experimental section was 53+23 (n=143). When the course was offered with the same instructor, cooperative learning, e-mail, but no grade/study-performance contract the ACS Exam percentile average 37+29. This represents a drop of 9.9 standard deviations for comparison of the means. We conclude that grade/study-performance contracts can be effective in increasing both student performance and retention in undergraduate organic chemistry.
An Environmental Chemistry Experiment: The Determination of Radon Levels in Water.
ERIC Educational Resources Information Center
Welch, Lawrence E.; Mossman, Daniel M.
Describes a radiation experiment developed to complement a new environmental chemistry laboratory curriculum. A scintillation counter is used to measure radon in water. The procedure relies on the fact that toluene will preferentially extract radon from water. Sample preparation is complete in less than 90 minutes. Because the level of…
Kounaves, Samuel P.
THE MARS ENVIRONMENTAL COMPATIBILITY ASSESSMENT (MECA) WET CHEMISTRY EXPERIMENT ON THE MARS '01 suite that will fly on the Mars Surveyor 2001 Lander Spacecraft. MECA is sponsored by the Human of Mars might present to astronauts and their equipment on a future human mission to Mars. Four elements
The U.S. Experience in Promoting Sustainable Chemistry (9 pp)
Joel A. Tickner; Ken Geiser; Melissa Coffin
Background, Aim and Scope. Recent developments in European chemicals policy, including the Registration, Evaluation and Au- thorization of Chemicals (REACH) proposal, provide a unique opportunity to examine the U.S. experience in promoting sus- tainable chemistry as well as the strengths and weaknesses of ex- isting policies. Indeed, the problems of industrial chemicals and limitations in current regulatory approaches to address
Suitable Class Experiments in Biochemistry for High-school Chemistry and Biology Courses.
ERIC Educational Resources Information Center
Myers, A.
Illustrates the scope of experimental investigations for biochemistry education in high school biology and chemistry courses. Gives a brief overview of biochemistry experiments with proteins, enzymes, carbohydrates, lipids, nucleic acids, vitamins, metabolism, electron transport, and photosynthesis including materials, procedures, and outcomes.…
Application of Calibrated Peer Review (CPR) Writing Assignments to Enhance Experiments with an Environmental Chemistry Focus
ERIC Educational Resources Information Center
Margerum, Lawrence D.; Gulsrud, Maren; Manlapez, Ronald; Rebong, Rachelle; Love, Austin
The browser-based software program, Calibrated Peer Review (CPR) developed by the Molecular Science Project enables instructors to create structured writing assignments in which students learn by writing and reading for content. Though the CPR project covers only one experiment in general chemistry, it might provide lab instructors with a method…
Nitration of Phenols Using Cu(NO[subscript 3])[subscript 2]: Green Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
Yadav, Urvashi; Mande, Hemant; Ghalsasi, Prasanna
An easy-to-complete, microwave-assisted, green chemistry, electrophilic nitration method for phenol using Cu(NO[subscript 3])[subscript 2] in acetic acid is discussed. With this experiment, students clearly understand the mechanism underlying the nitration reaction in one laboratory session. (Contains 4 schemes.)
Absorption and Scattering Coefficients: A Biophysical-Chemistry Experiment Using Reflectance Spectroscopy
ERIC Educational Resources Information Center
Cordon, Gabriela B.; Lagorio, M. Gabriela
A biophysical-chemistry experiment, based on the reflectance spectroscopy for calculating the absorption and scattering coefficients of leaves is described. The results show that different plants species exhibit different values for both the coefficients because of their different pigment composition.
Atmospheric Chemistry Experiment (ACE) Arctic stratospheric measurements of NOx during February and March 2004: Impact of
Nassar, Ray
,2 Peter Bernath,2 John C. McConnell,3 and Linda Chiou4 Received 12 January 2005; revised 28 March observations and model predictions. Citation: Rinsland, C. P., C. Boone, R. Nassar, K. Walker, P. Bernath, J. C. McConnell, and L. Chiou (2005), Atmospheric Chemistry Experiment (ACE) Arctic stratospheric
An Advanced Undergraduate Chemistry Laboratory Experiment Exploring NIR Spectroscopy and Chemometrics
ERIC Educational Resources Information Center
Wanke, Randall; Stauffer, Jennifer
An advanced undergraduate chemistry laboratory experiment to study the advantages and hazards of the coupling of NIR spectroscopy and chemometrics is described. The combination is commonly used for analysis and process control of various ingredients used in agriculture, petroleum and food products.
Molecular Orbitals of NO, NO[superscript+], and NO[superscript-]: A Computational Quantum Chemistry Experiment
ERIC Educational Resources Information Center
Orenha, Renato P.; Galembeck, Sérgio E.
This computational experiment presents qualitative molecular orbital (QMO) and computational quantum chemistry exercises of NO, NO[superscript+], and NO[superscript-]. Initially students explore several properties of the target molecules by Lewis diagrams and the QMO theory. Then, they compare qualitative conclusions with EHT and DFT calculations…
A Stopped-Flow Kinetics Experiment for the Physical Chemistry Laboratory Using Noncorrosive Reagents
ERIC Educational Resources Information Center
Prigodich, Richard V.
Stopped-flow kinetics techniques are important to the study of rapid chemical and biochemical reactions. Incorporation of a stopped-flow kinetics experiment into the physical chemistry laboratory curriculum would therefore be an instructive addition. However, the usual reactions studied in such exercises employ a corrosive reagent that can over…
Measurement of the Compressibility Factor of Gases: A Physical Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
Varberg, Thomas D.; Bendelsmith, Andrew J.; Kuwata, Keith T.
In this article, we describe an experiment for the undergraduate physical chemistry laboratory in which students measure the compressibility factor of two gases, helium and carbon dioxide, as a function of pressure at constant temperature. The experimental apparatus is relatively inexpensive to construct and is described and diagrammed in detail.…
Computational Modeling of the Optical Rotation of Amino Acids: An "in Silico" Experiment for Physical Chemistry
ERIC Educational Resources Information Center
Simpson, Scott; Autschbach, Jochen; Zurek, Eva
A computational experiment that investigates the optical activity of the amino acid valine has been developed for an upper-level undergraduate physical chemistry laboratory course. Hybrid density functional theory calculations were carried out for valine to confirm the rule that adding a strong acid to a solution of an amino acid in the l…
What Can We Do about "Parker"? A Case Study of a Good Student Who Didn't "Get" Organic Chemistry
ERIC Educational Resources Information Center
Anderson, Trisha L.; Bodner, George M.
This paper is based on a qualitative study of seven students enrolled in a two-semester organic chemistry course for chemistry and chemical engineering majors that focused on the reasoning the students had used to answer questions on the course exams. Narrative analysis was applied to create case records for each participant that were then…
The impact of recirculation, ventilation and filters on secondary organic aerosols generated by indoor chemistry
NASA Astrophysics Data System (ADS)
Fadeyi, M. O.; Weschler, C. J.; Tham, K. W.
This study examined the impact of recirculation rates (7 and 14 h -1), ventilation rates (1 and 2 h -1), and filtration on secondary organic aerosols (SOAs) generated by ozone of outdoor origin reacting with limonene of indoor origin. Experiments were conducted within a recirculating air handling system that serviced an unoccupied, 236 m 3 environmental chamber configured to simulate an office; either no filter, a new filter or a used filter was located downstream of where outdoor air mixed with return air. For otherwise comparable conditions, the SOA number and mass concentrations at a recirculation rate of 14 h -1 were significantly smaller than at a recirculation rate of 7 h -1. This was due primarily to lower ozone concentrations, resulting from increased surface removal, at the higher recirculation rate. Increased ventilation increased outdoor-to-indoor transport of ozone, but this was more than offset by the increased dilution of SOA derived from ozone-initiated chemistry. The presence of a particle filter (new or used) strikingly lowered SOA number and mass concentrations compared with conditions when no filter was present. Even though the particle filter in this study had only 35% single-pass removal efficiency for 100 nm particles, filtration efficiency was greatly amplified by recirculation. SOA particle levels were reduced to an even greater extent when an activated carbon filter was in the system, due to ozone removal by the carbon filter. These findings improve our understanding of the influence of commonly employed energy saving procedures on occupant exposures to ozone and ozone-derived SOA.
NSDL National Science Digital Library
Brahmadeo Dewprashad
This case study on the chemistry of cocaine is in the form of a classroom discussion between a professor and her students about cocaine, its addictive properties, a search for an addiction treatment, and the chemistry involved in the synthesis of cocaine in its various forms. The case can be used to teach nucleophilic addition reactions, nucleophilic acyl substitution, and cocaine metabolism. In addition, it provides students with experience in locating, reading, and analyzing a research paper. The case was designed for the second course in a two-course sequence in undergraduate organic chemistry, but it could be adapted for medicinal chemistry classes.
Thalidomide Makes a Comeback: A Case Discussion Exercise That Integrates Biochemistry and Organic Chemistry
NASA Astrophysics Data System (ADS)
Bennett, Nicole; Cornely, Kathleen
The case discussion method, which involves teaching scientific theory in a framework that students can relate to their own world, is an interdisciplinary pedagogical tool. Therefore, case study exercises can be used to integrate biochemistry with other advanced chemistry courses. The case presented here can be used at the end of a second-semester organic chemistry course or in an introductory biochemistry course. The case is a fact-based, fictional story in which an FDA official must decide whether to carry out the agency's threat to shut down several buyers clubs that import thalidomide from overseas and dispense it to their members for the treatment of AIDS. Students are required to read the body of the case, analyze data, and search for information using limited leads. Using well-considered arguments based on their research, they are asked to come to conclusions about how the element of risk involved in thalidomide distribution is assessed. They apply their knowledge of biochemistry to assess how thalidomide acts at the cellular level and they apply their knowledge of organic chemistry in writing mechanisms of thalidomide hydrolysis and in the design of thalidomide analogs. Students are assessed on their ability to work in groups, to critically analyze scientific data, and to develop public policies based on risk-benefit analysis.
The surface as molecular reagent: organic chemistry at the semiconductor interface
NASA Astrophysics Data System (ADS)
Filler, Michael A.; Bent, Stacey F.
Methods for the incorporation of organic functionality onto semiconductor surfaces have seen immense progress in recent years. Of the multiple methods developed, the direct, covalent attachment of organic moieties is valuable because it allows for excellent control of the interfacial properties. This review article will focus on a number of synthetic strategies that have been developed to exploit the unique reactivity of group-IV surfaces under vacuum. A picture of the semiconductor surface and its reactions will be developed within the standard framework of organic chemistry with emphasis on the importance of combined experimental and theoretical approaches. Three broad areas of organic chemistry will be highlighted, including nucleophilic/electrophilic, pericyclic, and aromatic reactions. The concept of nucleophilicity and electrophilicity will be discussed within the context of dative bonding and proton transfer of amines and alcohols. Pericyclic reactions cover the [4 + 2] or Diels-Alder cycloaddition, [2 + 2] cycloaddition, dipolar, and ene reactions. Examples include the reactions of alkenes, dienes, ketones, nitriles, and related multifunctional molecules at the interface. Aromaticity and the use of directing groups to influence the distribution of surface products will be illustrated with benzene, xylene, and heteroaromatic compounds. Finally, multifunctional molecules are used to describe the competition and selectively observed among different surface reactions.
Developments and plans for new drifting balloon experiments in the Chemistry-Aerosol Mediterranean Experiment (ChArMEx) project
François Dulac; Pierre Durand; Nicolas Verdier; Jean-Baptiste Renard; Marc Mallet; Valérie Thouret; Jean-Luc Attié
ChArMEx (the Chemistry-Aerosol Mediterranean Experiment; http:\\/\\/charmex.lsce.ipsl.fr) is a new integrated project which aims at an assessment of the present state of the atmospheric environment in the Mediterranean basin, of its impacts on air quality, regional climate and marine biogeochemistry, and of their evolution in a regional context of intense climate change and increasing anthropogenic pressure. The Mediterranean is indeed characterized
Preparation of cyclodextrin chiral stationary phases by organic soluble catalytic 'click' chemistry.
Wang, Yong; Chen, Hui; Xiao, Yin; Ng, Cheong Hengq; Oh, Ting Shan; Tan, Timothy Thatt Yang; Ng, Siu Choon
We describe an effective and simple protocol that uses click chemistry to attach native ?-cyclodextrin (?-CD) to silica particles, resulting in a chiral stationary phase (CCNCSP) that can be used for the enantioseparation of chiral drugs by high-performance liquid chromatography (HPLC). Starting from ?-CD, the CCNCSP is prepared in several steps: (i) reaction of ?-CD with 1-(p-toluenesulfonyl)-imidazole to afford mono-6-toluenesulfonyl-?-CD; (ii) azidolysis of mono-6-toluenesulfonyl-?-CD in dimethylformamide to give mono-6-azido-?-CD (N(3)-CD); (iii) reaction of cuprous iodide with triphenylphosphine to form an organic soluble catalyst CuI(PPh(3)); (iv) preparation of alkynyl-modified silica particles; and (v) click chemistry immobilization of N(3)-CD onto alkynyl-modified silica to afford the desired chiral stationary phase. Synthesis of the stationary phase and column packing takes ?1 week. PMID:21720308
ERIC Educational Resources Information Center
School Science Review, 1978
Describes experiments, demonstrations, activities and ideas relating to various fields of chemistry to be used in chemistry courses of secondary schools. Three experiments concerning differential thermal analysis are among these notes presented. (HM)
BachelorofScience/BachelorofEducation Chemistry/ScienceEducation
Morris, Joy
- Organic Chemistry II ___ 6. Chemistry 2740 - Physical Chemistry List B - Elective Chemistry - Contemporary Chemistry ___Chemistry 3410 - Analytical Chemistry II ___Chemistry 3730 - Advanced PhysicalBachelorofScience/BachelorofEducation Chemistry/ScienceEducation This is a planning guide
Explicit modeling of organic chemistry and secondary organic aerosol partitioning for Mexico City and its outflow plume
NASA Astrophysics Data System (ADS)
Lee-Taylor, J.; Madronich, S.; Aumont, B.; Baker, A.; Camredon, M.; Hodzic, A.; Tyndall, G. S.; Apel, E.; Zaveri, R. A.
The evolution of organic aerosols (OA) in Mexico City and its outflow is investigated with the nearly explicit gas phase photochemistry model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere), wherein precursor hydrocarbons are oxidized to numerous intermediate species for which vapor pressures are computed and used to determine gas/particle partitioning in a chemical box model. Precursor emissions included observed C3-10 alkanes, alkenes, and light aromatics, as well as larger n-alkanes (up to C25) not directly observed but estimated by scaling to particulate emissions according to their volatility. Conditions were selected for comparison with observations made in March 2006 (MILAGRO). The model successfully reproduces the magnitude and diurnal shape for both primary (POA) and secondary (SOA) organic aerosols, with POA peaking in the early morning at 15-20 ?g m-3, and SOA peaking at 10-15 ?g m-3 during mid-day. The majority (?75%) of the model SOA stems from reaction products of the large n-alkanes, used here as surrogates for all emitted hydrocarbons of similar volatility, with the remaining SOA originating mostly from the light aromatics. Simulated OA elemental composition reproduces observed H/C and O/C ratios reasonably well, although modeled ratios develop more slowly than observations suggest. SOA chemical composition is initially dominated by ?-hydroxy ketones and nitrates from the large alkanes, with contributions from peroxy acyl nitrates and, at later times when NOx is lower, organic hydroperoxides. The simulated plume-integrated OA mass continues to increase for several days downwind despite dilution-induced particle evaporation, since oxidation chemistry leading to SOA formation remains strong. In this model, the plume SOA burden several days downwind exceeds that leaving the city by a factor of >3. These results suggest significant regional radiative impacts of SOA.
Explicit modeling of organic chemistry and secondary organic aerosol partitioning for Mexico City and its outflow plume
NASA Astrophysics Data System (ADS)
Lee-Taylor, J.; Madronich, S.; Aumont, B.; Camredon, M.; Hodzic, A.; Tyndall, G. S.; Apel, E.; Zaveri, R. A.
The evolution of organic aerosols (OA) in Mexico City and its outflow is investigated with the nearly explicit gas phase photochemistry model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere), wherein precursor hydrocarbons are oxidized to numerous intermediate species for which vapor pressures are computed and used to determine gas/particle partitioning in a chemical box model. Precursor emissions included observed C3-10 alkanes, alkenes, and light aromatics, as well as larger n-alkanes (up to C25) not directly observed but estimated by scaling to particulate emissions according to their volatility. Conditions were selected for comparison with observations made in March 2006 (MILAGRO). The model successfully reproduces the magnitude and diurnal shape for both primary (POA) and secondary (SOA) organic aerosols, with POA peaking in the early morning at 15-20 ?g m-3, and SOA peaking at 10-15 ?g m-3 during mid-day. The majority (?75 %) of the model SOA stems from the large n-alkanes, with the remainder mostly from the light aromatics. Simulated OA elemental composition reproduces observed H/C and O/C ratios reasonably well, although modeled ratios develop more slowly than observations suggest. SOA chemical composition is initially dominated by ?-hydroxy ketones and nitrates from the large alkanes, with contributions from peroxy acyl nitrates and, at later times when NOx is lower, organic hydroperoxides. The simulated plume-integrated OA mass continues to increase for several days downwind despite dilution-induced particle evaporation, since oxidation chemistry leading to SOA formation remains strong. In this model, the plume SOA burden several days downwind exceeds that leaving the city by a factor of >3. These results suggest significant regional radiative impacts of SOA.
Explicit modeling of organic chemistry and secondary organic aerosol partitioning for Mexico City and its outflow plume
Lee-Taylor, J.; Madronich, Sasha; Aumont, B.; Baker, A.; Camredon, M.; Hodzic, Alma; Tyndall, G. S.; Apel, Eric; Zaveri, Rahul A.
The evolution of organic aerosols (OA) in Mexico City and its outflow is investigated with the nearly explicit gas phase photochemistry model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere), wherein precursor hydrocarbons are oxidized to numerous intermediate species for which vapor pressures are computed and used to determine gas/particle partitioning in a chemical box model. Precursor emissions included observed C3-10 alkanes, alkenes, and light aromatics, as well as larger n-alkanes (up to C25) not directly observed but estimated by scaling to particulate emissions according to their volatility. Conditions were selected for comparison with observations made in March 2006 (MILAGRO). The model successfully reproduces the magnitude and diurnal shape for both primary (POA) and secondary (SOA) organic aerosols, with POA peaking in the early morning at 15-20 ug m-3, and SOA peaking at 10-15 ?g m-3 during mid-day. The majority (> 75%) of the model SOA stems from the large n-alkanes, with the remainder mostly from the light aromatics. Simulated OA elemental composition reproduces observed H/C and O/C ratios reasonably well, although modeled ratios develop more slowly than observations suggest. SOA chemical composition is initially dominated by *- hydroxy ketones and nitrates from the large alkanes, with contributions from peroxy acyl nitrates and, at later times when NOx is lower, organic hydroperoxides. The simulated plume-integrated OA mass continues to increase for several days downwind despite dilution-induced particle evaporation, since oxidation chemistry leading to SOA formation remains strong. In this model, the plume SOA burden several days downwind exceeds that leaving the city by a factor of >3. These results suggest significant regional radiative impacts of SOA.
Model analysis of secondary organic aerosol formation by glyoxal in laboratory studies: the case for photoenhanced chemistry.
Sumner, Andrew J; Woo, Joseph L; McNeill, V Faye
The reactive uptake of glyoxal by atmospheric aerosols is believed to be a significant source of secondary organic aerosol (SOA). Several recent laboratory studies have been performed with the goal of characterizing this process, but questions remain regarding the effects of photochemistry on SOA growth. We applied GAMMA (McNeill et al. Environ. Sci. Technol. 2012, 46, 8075-8081), a photochemical box model with coupled gas-phase and detailed aqueous aerosol-phase chemistry, to simulate aerosol chamber studies of SOA formation by the uptake of glyoxal by wet aerosol under dark and irradiated conditions (Kroll et al. J. Geophys. Res. 2005, 110 (D23), 1-10; Volkamer et al. Atmos. Chem. Phys. 2009, 9, 1907-1928; Galloway et al. Atmos. Chem. Phys. 2009, 9, 3331- 306 3345 and Geophys. Res. Lett. 2011, 38, L17811). We find close agreement between simulated SOA growth and the results of experiments conducted under dark conditions using values of the effective Henry's Law constant of 1.3-5.5 × 10(7) M atm(-1). While irradiated conditions led to the production of some organic acids, organosulfates, and other oxidation products via well-established photochemical mechanisms, these additional product species contribute negligible aerosol mass compared to the dark uptake of glyoxal. Simulated results for irradiated experiments therefore fell short of the reported SOA mass yield by up to 92%. This suggests a significant light-dependent SOA formation mechanism that is not currently accounted for by known bulk photochemistry, consistent with recent laboratory observations of SOA production via photosensitizer chemistry. PMID:25226456
Control of interfacial chemistry and reactivity using self-assembled organic films
NASA Astrophysics Data System (ADS)
Mao, Guoqiang
Ultrathin organic films have been fabricated using both polymers and monomers on solid supports. Interfacial chemistry was controlled and characterized for these surfaces with the intention of applying well-controlled surface chemistry to study interfacial interactions in biological systems. Polysiloxanes grafted with either alkyl disulfide or trichlorosilane anchor groups and perfluoroalkyl side chains have been synthesized and characterized. These terpolymer systems assemble spontaneously on gold or silicon wafer surfaces, forming bound polymeric monolayers organized by intramolecular phase separation. A variety of surface analytical techniques has been used to show that immiscible perfluoroalkyl side chains of low interfacial energy enrich the ambient-exposed outer regions of these monolayers, yielding a novel bound polymer monolayer with an anisotropic, layered structure and perfluorinated surface properties. Polymer-modified ultrathin films have also been fabricated by covalent immobilization of hydrophobic and hydrophilic polymers in sequential reactions to olefin-terminated alkylsilane monolayers on silicon oxide. Film surface chemistry and interfacial energy are modified significantly using this approach. Monomer omega-functionalized alkylthiol molecules have been synthesized as organic monolayer components. Surface analytical measurements show that these molecules form good quality monolayer structures on gold $ surfaces. These well-tailored self-assembled monolayer (SAM) surfaces were used as model interfaces in biological milieu. Amino acid-substituted mutants of bacteriophage T4 lysozyme were used to study mutual influences of protein structure and monolayer surface chemistry. In-situ ellipsometry was applied to study the adsorption kinetics of these site-directed T4 lysozyme mutanes to the different self-assembled monolayer surfaces. Protein adsorption kinetics and equilibrium adsorbed amounts are influenced by surface properties, protein structure, and protein stability. T4 lysozyme adsorption behavior appears to depend on many aspects of surface chemistry, not simply surface hydrophobicity. Oligo(ethylene glycol) terminated surfaces show the lowest T4 lysozyme adsorption. Molecular modeling which includes protein-protein interactions shows reasonable fits for protein adsorption curves. Kinetic parameters indicated that the least structurally stable tryptophan T4 lysozyme mutant adsorbs to -CHsb3, -CFsb3$ and -COOH terminated self-assembled monolayers faster and tighter than the other T4 lysozyme mutants.
Integrated management systems: experiences in Italian organizations
Roberta Salomone
Integrated Management Systems (IMS) are becoming more and more important, but experiences may differ across regions and companies of different size and sectors. The study reported in this paper has been developed using a sample of Italian companies to investigate the potential for integration starting from an analysis of the common aspects in terms of real motivations (company image, costs
The Organization of Reports of Scientific Experiments.
ERIC Educational Resources Information Center
Sawyer, Thomas M.
Beginning teachers of scientific technical writing often have little background knowledge in the sciences; thus, they may encounter difficulty in dealing with technical reports. To achieve clear explanations of the effects of scientific experiments, scientific writers need to know the following general principles: (1) the function of all the…
"Crown Ether" Synthesis: An Organic Laboratory Experiment.
ERIC Educational Resources Information Center
Field, Kurt W.; And Others
This experiment is designed to acquaint the student with a macromolecular synthesis of a crown ether type compound. The starting materials are readily available and the product, a cyclic polyether, belongs to a class of compounds that has aroused the interest of chemist and biologist alike. (Author/BB)
Explicit Modeling of Organic Chemistry and SOA Partitioning in Mexico City
NASA Astrophysics Data System (ADS)
Lee-Taylor, J.; Madronich, S.; Aumont, B.; Camredon, M.; Apel, E. C.; Hodzic, A.; Tyndall, G. S.; Valorso, R.
We use the GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere) model to simulate the composition of organic aerosol in Mexico City's urban atmosphere and outflow plume during the MILAGRO campaign. The mechanism is extremely detailed, treating 5.9 million gas phase reactions among > 1 million species. Gas/aerosol partitioning is treated by Raoult's law-type condensation for > 275 000 non-radical species. We are able to speciate the simulated primary and secondary organic aerosol (POA and SOA) and find that it is distributed somewhat equally between species of different carbon number (with C>5), despite large disparities in emissions and gas-phase abundance. Over 90% of the total burden of C23+ carbon is present as POA. Close to the source region, the simulated SOA is composed predominantly of delta-hydroxy-ketones and hydroxy-nitrates. SOA functionality becomes more diverse with age downwind, reflecting a shift from high-NOx to low-NOx chemistry within the plume. In addition, the degree of substitution increases as SOA ages, resulting in greater relative contributions from lower carbon-number species. Compared to observations, the modeled O/C ratio of the aerosol is lower and the N/C ratio is higher, suggesting that additional important reaction pathways either in the gas or the particle phase remain to be elucidated.
Solvent Selection for Recrystallization: An Undergraduate Organic Experiment.
ERIC Educational Resources Information Center
Baumann, Jacob B.
This experiment develops the students' ability to carry out a simple recrystallization effectively, and demonstrates how a solvent may be selected or rejected for the recrystallization of a specific organic compound. (Author/BB)
A facile route to prepare organic/inorganic hybrid nanomaterials by 'click chemistry'.
Lu, Xunyu; Sun, Fu; Wang, Jing; Zhong, Jianfeng; Dong, Qingzhi
An organosilane with an alkyne group at the non-condensable end, [(2-propynylcarbamate)propyl]triethoxysilane, has been synthesized. Condensation of this organosilane with tetraethoxysilane can be achieved by a co-condensation strategy to produce silica nanoparticles with surface alkyne functionality. The size and uniformity of size distribution of the silica nanoparticles are influenced by varying the concentration of the added organosilane. The alkyne-functionalized silica nanoparticles are coupled directly with azide-modified polymers by 'click chemistry' to yield organic-inorganic hybrid nanomaterials. PMID:21638504
The Isolation of Rubber from Milkweed Leaves. An Introductory Organic Chemistry Lab
NASA Astrophysics Data System (ADS)
Volaric, Lisa; Hagen, John P.
We present an introductory organic chemistry lab in which students isolate rubber from the leaves of milkweed plants (Asclepias syriaca). Students isolated rubber with a recovery of 2.4 ± 1.8% and 1.8 ± 0.7% for the microscale and macroscale procedures, respectively. Infrared spectra of their products were compared with the spectrum of synthetic rubber, cis-polyisoprene. Students tested for elasticity of their product by twisting it on a spatula and pulling; all students found some degree of elasticity.
Fostering Pre-service Teachers' Self-Determined Environmental Motivation Through Green Chemistry Experiments
NASA Astrophysics Data System (ADS)
Karpudewan, Mageswary; Ismail, Zurida; Roth, Wolff-Michael
The global environmental crisis intensifies particularly in developing nations. Environmental educators have begun to understand that changing the environmental impact requires not only changes in pro-environmental knowledge and attitudes but also in associated, self-determined motivation. This study was designed to test the hypothesis that a green chemistry curriculum changes Malaysian pre-service teachers' environmental motivation. Two comparable groups of pre-service teachers participated in this study. The students in the experimental group ( N = 140) did green chemistry experiments whereas the control group ( N = 123) did equivalent experiments in a traditional manner. Posttest results indicate that there is significant difference between both the groups for intrinsic motivation, integration, identification, and introjections scales and no differences for external regulation and amotivation scales. The qualitative analysis of interview data suggests that the changes are predominantly due to the personal satisfaction that participants derived from engaging in pro-environmental behavior.
A Fifty-Year Love Affair with Organic Chemistry (by William S. Johnson)
NASA Astrophysics Data System (ADS)
Kauffman, Reviewed By George B.; Kauffman, Laurie M.
This latest volume is the 20th in Jeff Seeman's projected 22-volume series of autobiographies of 20th-century organic chemists that began publication in 1990 (Kauffman, G. B. J. Chem. Educ. 1991, 68, A21). Unfortunately, Johnson did not live to see this volume in print. Ted Bartlett and Ray Conrow reviewed the final manuscript, galleys, and page proofs; and Ted Bartlett, Paul Bartlett, John D. Roberts, and Gilbert Stork contributed an epilogue that complements Johnson's own words, adds a warm, personal final touch that he was unable to provide, and incorporates his final research into the volume. Born in New Rochelle, New York, on February 24, 1913, William Summer Johnson attended Amherst College with the aid of a scholarship and various odd jobs such as tending furnace, washing dishes, and playing saxophone in dance bands (he seriously considered becoming a professional musician). Here he became enamored with organic chemistry, which he taught as an instructor for a year after his graduation magna cum laude in 1936. He then worked with a fellowship under Louis Fieser, who sparked his interest in steroids, at Harvard University, from which he received his M.A. (1938) and Ph.D. (1940) degrees. In 1940 Johnson joined the faculty at the University of Wisconsin, where he rose through the ranks, eventually becoming Homer Adkins Professor of Chemistry (1954-60). He began the total synthesis of steroids, the main subject of his life's work, "which soon proved to be the hottest synthetic target of the time". In 1960 he accepted an invitation to become head of and to upgrade the Stanford University Chemistry Department. With faculty recruiting as his primary concern, he was able to add Carl Djerassi, Paul J. Flory, Harden M. McConnell, Henry Taube, and Eugene E. van Tamelen to the department, resulting in its spectacular rise from 15th to 5th place in the nation. He remained at Stanford for the rest of his career, serving as department head for nine years. He died at the age of 82 on August 19, 1995. Johnson's book reads like a Who's Who of Organic Chemistry, with descriptions, impressions, and thumbnail sketches of such luminaries as Sir Robert Robinson, Robert B. Woodward, Gilbert Stork, Carl Djerassi, Derek Barton, John D. ("Jack") Roberts, and authors of other Profiles volumes. During his long and productive career, Johnson made many contributions to contemporary organic chemistry, the genesis and course of which he describes lucidly with extensive use of 110 structural formulas, 75 reaction schemes, and occasional laboratory notebook pages. Three hundred fifty-six graduate and undergraduate students, postdocs, and visiting professors (many of whom are shown in the 63 formal and informal photographs in the book) have worked with him through five and a half decades. In "Some Concluding Remarks about Our Research", Johnson states, "The reviewed research did not evolve from a master plan; indeed it was largely a matter of following one's nose and trying to look at things that related to areas that were regarded as important issues of the time." Johnson's intimate and revealing autobiography will not only appeal to synthetic organic chemists but will be of interest to both present and future generations of students and instructors of chemistry courses and the history of science as well as to all persons concerned with the human aspects of science.
Designing Undergraduate-Level Organic Chemistry Instructional Problems: Seven Ideas from a Problem-Solving Study of Practicing Synthetic Organic Chemists
ERIC Educational Resources Information Center
Raker, Jeffrey R.; Towns, Marcy H.
The development of curricular problems based on the practice of synthetic organic chemistry has not been explored in the literature. Such problems have broadly been hypothesized to promote student persistence and interest in STEM fields. This study reports seven ideas about how practice-based problems can be developed for sophomore-level organic…
Impacts of organic nitrate chemistry on NOx and O3 in California: Model results and comparisons to observations
NASA Astrophysics Data System (ADS)
Browne, E. C.; Valin, L. C.; Cohen, R. C.; LaFranchi, B. W.; Min, K.; Perring, A. E.; Pusede, S. E.; Wooldridge, P. J.
Organic nitrates, formed by a minor channel of the NO + RO2 reaction, represent a termination step of ozone production. Organic nitrate formation becomes most significant in the cross-over regime between NOx saturated (VOC limited) and NOx limited ozone production and, therefore, may have a significant impact on ozone photochemistry in urban outflows. Although numerous observations show that organic nitrates can represent a significant fraction (up to ~20%) of oxidized nitrogen, current regional chemistry models contain an inadequate representation of organic nitrates. We have developed a more realistic parameterization of organic nitrate chemistry that treats monofunctional, multifunctional saturated, multifunctional unsaturated, aromatic, isoprene, and monoterpene nitrates as unique model species with appropriate lifetimes and NOx recycling efficiencies. This chemistry has been incorporated into the WRF-Chem three dimensional regional chemistry model. Using a combination of model results and organic nitrate observations from ground and airborne measurements, we investigate how organic nitrate concentration and composition vary throughout California. Additionally, we analyze how organic nitrate formation impacts NOx lifetime and ozone production.
Mechanisms before Reactions: A Mechanistic Approach to the Organic Chemistry Curriculum Based on Patterns of Electron Flow
ERIC Educational Resources Information Center
Flynn, Alison B.; Ogilvie, William W.
A significant redesign of the introductory organic chemistry curriculum at the authors' institution is described. There are two aspects that differ greatly from a typical functional group approach. First, organic reaction mechanisms and the electron-pushing formalism are taught before students have learned a single reaction. The conservation of…
Incorporation of the CrossFire Beilstein Database into the Organic Chemistry Curriculum at the Royal Danish School of Pharmacy
S. Brřgger Christensen; Henrik Franzyk; Bente Frřlund; Jerzy W. Jaroszewski; Dan Stćrk; Per Vedsř
The CrossFire Beilstein database has been incorporated into the organic chemistry curriculum at the Royal Danish School of Pharmacy as a powerful pedagogic tool. During a laboratory course in organic synthesis the database enables the students to get comprehensive overviews of known synthetic methods for a given compound. During a laboratory course in identification and as a part of an
Meaningful Learning in a First-Year Chemistry Laboratory Course: Differences across Classical, Discovery, and Instrumental Experiments
ERIC Educational Resources Information Center
Emenike, Mary Elizabeth; Danielson, Neil D.; Bretz, Stacey Lowery
At Miami University in Oxford, Ohio, the second-semester general chemistry course for chemistry majors is the equivalent of an analytical laboratory course. The experiments in the course are classified as classical, discovery, or instrumental on the basis of their structure and purpose. To investigate students' perceptions of learning through…
S.E.A. Lab. Science Experiments and Activities. Marine Science for High School Students in Chemistry, Biology and Physics.
ERIC Educational Resources Information Center
Hart, Kathy, Ed.
A series of science experiments and activities designed for secondary school students taking biology, chemistry, physics, physical science or marine science courses are outlined. Each of the three major sections--chemistry, biology, and physics--addresses concepts that are generally covered in those courses but incorporates aspects of marine…
Introduction to Homogenous Catalysis with Ruthenium-Catalyzed Oxidation of Alcohols: An Experiment for Undergraduate Advanced Inorganic Chemistry Students
ERIC Educational Resources Information Center
Miecznikowski, John R.; Caradonna, John P.; Foley, Kathleen M.; Kwiecien, Daniel J.; Lisi, George P.; Martinez, Anthony M.
A three-week laboratory experiment, which introduces students in an advanced inorganic chemistry course to air-sensitive chemistry and catalysis, is described. During the first week, the students synthesize RuCl[subscript 2](PPh[subscript 3])[subscript 3]. During the second and third weeks, the students characterize the formed coordination…
The Role of Radiation in the Solar Nebula: Correlated Chemistry-Structure- Isotope Studies of Laboratory and Extraterrestrial Organics
NASA Astrophysics Data System (ADS)
Nittler, Larry
This proposal outlines an interdisciplinary effort aimed at quantitatively evaluating the roles that irradiation played in the evolution of ices and organics in the solar nebula and the potential trapping of noble gases in primitive solids. The collective effort outlined here and in two partnered proposals (PIs Scott Sandford and Fred Ciesla) involves individuals at five primary institutions. We define a series of coordinated experimental, theoretical, and observational projects that are necessary to begin to recognize and understand the complex effects of irradiation in the early Solar System. This coordinated effort is in line with the latest emphasis on interdisciplinary work by the Origins of Solar System program. The specific goal of the CIW-NRL component of the effort is to conduct comparative studies of the isotope composition, chemistry and structure of organic residues from ices subjected to controlled radiation exposures, with those of organic matter in primitive Solar System materials, primarily interplanetary dust particles (IDPs). Three broad tasks will be undertaken: 1) Evaluate the extent to which organic molecules were formed and restructured as they and their icy precursors were irradiated by UV, x-rays and cosmic-rays in the solar nebula. Specifically, we will revisit the model of Ciesla and Sandford (Science, 2012), and evaluate the irradiation doses seen by ices and organics in the disk, as well as the chemical evolution of these species as they move through more realistic disk structures. The detailed consequences of this irradiation, as well as the rates and fluences required to drive changes in chemistry and physical structure, will be determined by complementary experiments and analytic studies. 2) Quantitatively explore the history of noble gases in ices and organics in the outer solar nebula as water ice is desorbed (due to thermal or photo effects) and reformed in the solar nebula. We will also explore how such ices are irradiated and the structural changes that occur in these ices and resulting photo-products. We will determine the extent to which noble gases remain trapped in these ices after processing and in the residues that form from this irradiation, and the extent to which this residue replicates the properties of the enigmatic phase Q carrier of noble gases in meteorites. 3) Determine the isotopic effects of C, H, and N induced by irradiation of ices and organics. We will carry out experiments to determine how enrichments in heavy isotopes may be passed forward from target ices into organics and the extent to which irradiation itself results in isotopic differences between target materials and residues. These results will be combined with dynamical models to determine the range of isotopic ratios expected from irradiative processing in the solar nebula. Each of these experimental and theoretical tasks will be complemented by coordinated microanalytical (chemical-microstructural-isotopic) studies of relevant, naturally- occurring, organic matter in anhydrous chondritic porous IDPs and, if available, ultracarbonaceous micrometeorites. Both are among the most primitive planetary materials available for laboratory study. These observations will be used to better understand the range of properties of early Solar System organic matter and to directly search for evidence of the radiation processing signatures identified by the three major tasks above. Thus, the IDP and micrometeorite analyses are necessary to provide ground-truth for the extensive theoretical and experimental work.
Mather, Patrick T.
Fall 2011 Chemistry 676 "Introduction to organic synthesis: Methodology" T chemistry, olefination reactions, cross coupling chemistry, and modern transition metal are due by 1200 (noon) in my office (CST 3-008) or my mailbox in the chemistry
Distinct Optical Chemistry of Dissolved Organic Matter in Urban Pond Ecosystems
McEnroe, Nicola A.; Williams, Clayton J.; Xenopoulos, Marguerite A.; Porcal, Petr; Frost, Paul C.
Urbanization has the potential to dramatically alter the biogeochemistry of receiving freshwater ecosystems. We examined the optical chemistry of dissolved organic matter (DOM) in forty-five urban ponds across southern Ontario, Canada to examine whether optical characteristics in these relatively new ecosystems are distinct from other freshwater systems. Dissolved organic carbon (DOC) concentrations ranged from 2 to 16 mg C L-1 across the ponds with an average value of 5.3 mg C L-1. Excitation-emission matrix (EEM) spectroscopy and parallel factor analysis (PARAFAC) modelling showed urban pond DOM to be characterized by microbial-like and, less importantly, by terrestrial derived humic-like components. The relatively transparent, non-humic DOM in urban ponds was more similar to that found in open water, lake ecosystems than to rivers or wetlands. After irradiation equivalent to 1.7 days of natural solar radiation, DOC concentrations, on average, decreased by 38% and UV absorbance decreased by 25%. Irradiation decreased the relative abundances of terrestrial humic-like components and increased protein-like aspects of the DOM pool. These findings suggest that high internal production and/or prolonged exposure to sunlight exerts a distinct and significant influence on the chemistry of urban pond DOM, which likely reduces its chemical similarity with upstream sources. These properties of urban pond DOM may alter its biogeochemical role in these relatively novel aquatic ecosystems. PMID:24348908
Organ yield from deceased donors: initial experience of an organ procurement unit in Iran.
Kazemeyni, Seyed-Mohammad; Sorosh, Ahmad-Reza; Afzali, Ahmad
To promote organ transplantation in Iran, organ procurement from deceased donors should be supported. For this policy, some organ procurement units have been established in university hospitals. Further researches in these activities are warranted to better elucidate the role of cadaveric organ transplantation in Iran.We retrospectively studied deceased organ donation from June 2005 through December 2007 in Organ Procurement Unit of Shariati Hospital in Tehran. We analyzed a total of 141 organs that were retrieved from 46 brain-dead organ donors.The median age of all donors was 29 years (min: six, max: 63). Two third of them were males. The average of harvested organs was 3.06 per donor and four organs per month. The main cause of brain death was head trauma (n=33, 72%). Organ yield per donor was correlated to the time of the organ procurement unit activity and increased during the three years (r=0.261, P=0.017). Other variables were not changed during this period. Donor characteristics such as age, sex, blood group, and causes of brain death impacted on the organ yield. This study showed that organ procurement units can improve organ yield and both experience and donor characteristics influence on the number of harvested organs. PMID:19249888
Do Long-Term Changes in Organic Matter Inputs to Forest Soils Affect Dissolved Organic Matter Chemistry and Export?
NASA Astrophysics Data System (ADS)
Lajtha, K.; Strid, A.; Lee, B. S.
Dissolved organic matter (DOM) production and transport play an important role in regulating organic matter (OM) distribution through a soil profile and ultimately, OM stabilization or export to aquatic systems. The contributions of varying OM inputs to the quality and amount of DOM as it passes through a soil profile remain relatively unknown. The Detrital Input and Removal Treatment (DIRT) site at the H. J. Andrews Experimental Forest in Oregon has undergone 17 years of litter, wood and root input manipulations and allows us to guage shifts in DOM chemistry induced by long-term changes to aboveground and belowground OM additions and exclusions. Using fluorescence and UV spectroscopy to characterize fluorescent properties, extent of decomposition, and sources of DOM in streams and soil solutions collected with lysimeters and soil extractions, we have assessed the importance of fresh OM inputs to DOM chemistry. Soil extracts from DIRT plots had a higher fluorescence index (FI) than lysimeter solutions or stream water. A high FI in surface water is generally interpreted as indicative of a high proportion of microbially-derived DOM. However, we suspect that the high FI in soil extracts is due to a higher proportion of non-aromatic DOM from fresh soil that microorganisms consume in transit through the soil profile to lysimeters or to streams. High redox index (RI) values were observed in lysimeters from the April 2014 sampling compared with the November 2013 sampling. These RI values show evidence of more reducing conditions at the end of the rainy season in the spring compared to the onset of the rainy season in the fall. Lysimeter water collected in No Input, No Litter, and No Root treatments contained high proportions of protein, suggesting the absence of carbon inputs changes activities of the microbial community. Observed variations reflect the viability of using fluorescent properties to explore the terrestrial-aquatic interface.
Measurement of the Order Parameter in a Room Temperature Liquid Crystal: An Experiment for the Physical Chemistry Laboratory.
ERIC Educational Resources Information Center
DuPre, Donald B.; Chapoy, L. Lawrence
Presented here is a laboratory experiment for a course in physical chemistry. Students are requested to directly measure the degree of orientational order in a liquid crystal at room temperature. A minimum amount of equipment is necessary. (Author/SA)
The fate or organic matter during planetary accretion - Preliminary studies of the organic chemistry of experimentally shocked Murchison meteorite
NASA Technical Reports Server (NTRS)
Tingle, Tracy N.; Tyburczy, James A.; Ahrens, Thomas J.; Becker, Christopher H.
The fate of organic matter in carbonaceous meteorites during hypervelocity (1-2 km/sec) impacts is investigated using results of experiments in which three samples of the Murchison (CM2) carbonaceous chondrite were shocked to 19, 20, and 36 GPa and analyzed by highly sensitive thermal-desorption photoionization mass spectrometry (SALI). The thermal-desorptive SALI mass spectra of unshocked CM2 material revealed presence of indigenous aliphatic, aromatic, sulfur, and organosulfur compounds, and samples shocked to about 20 GPa showed little or no loss of organic matter. On the other hand, samples shocked to 36 GPa exhibited about 70 percent loss of organic material and a lower alkene/alkane ratio than did the starting material. The results suggest that it is unlikely that the indigenous organic matter in carbonaceous chondritelike planetesimals could have survived the impact on the earth in the later stages of earth's accretion.
Insights into aerosol formation chemistry from comprehensive gas-phase precursor measurement in the ACES chamber experiments
NASA Astrophysics Data System (ADS)
Carr, Timo; Wyche, Kevin; Monks, Paul; Alfarra, Rami; McFiggans, Gordon; Ryan, Annette
Chemical Ionisation Reaction Time-of-Flight Mass Spectrometry (CIR-TOF-MS) was employed to observe, in real-time, the gas phase photooxidative evolution of eight different biogenic volatile organic compounds (BVOCs) believed to constitute precursors to secondary organic aerosol (SOA). As well as being used to monitor BVOC SOA precursor evolution, CIR-TOF-MS was also employed to monitor the formation of the multitudinous volatile and semi-volatile oxidation products formed. In total 27 different chamber style experiments were conducted at 'high' (ca. 250 ppbV) and 'low (ca. 50 ppbV) initial concentrations as part of the ACES (Aerosol Coupling in the Earth System) project at the University of Manchester aerosol chamber facility along with 11 mescosm experiments. The work presented will focus upon the observations made of the limonene oxidation system. A number of limonene oxidation products were detected including primary aldehyde and acid species (e.g. MCM designation LIMAL. Experiments seeded with ammonium sulphate exhibited a similar distribution of gas phase species, implying that any differences in aerosol formation/composition are not a result of the gas phase chemistry of the system. A total of up to 40 ions were detected under high concentration levels compared to 20 ions during low concentration experiments. During the mesocosm experiment, tropical Fig tree species were observed to emit large amounts of isoprene, with little monoterpene emission, whereas a reverse trend was observed from European birch species , signifying possible suppression of aerosol formation in the presence of high levels of isoprene.
Chemistry of decomposition of freshwater wetland sedimentary organic material during ramped pyrolysis
NASA Astrophysics Data System (ADS)
Williams, E. K.; Rosenheim, B. E.
Ramped pyrolysis methodology, such as that used in the programmed-temperature pyrolysis/combustion system (PTP/CS), improves radiocarbon analysis of geologic materials devoid of authigenic carbonate compounds and with low concentrations of extractable authochthonous organic molecules. The approach has improved sediment chronology in organic-rich sediments proximal to Antarctic ice shelves (Rosenheim et al., 2008) and constrained the carbon sequestration potential of suspended sediments in the lower Mississippi River (Roe et al., in review). Although ramped pyrolysis allows for separation of sedimentary organic material based upon relative reactivity, chemical information (i.e. chemical composition of pyrolysis products) is lost during the in-line combustion of pyrolysis products. A first order approximation of ramped pyrolysis/combustion system CO2 evolution, employing a simple Gaussian decomposition routine, has been useful (Rosenheim et al., 2008), but improvements may be possible. First, without prior compound-specific extractions, the molecular composition of sedimentary organic matter is unknown and/or unidentifiable. Second, even if determined as constituents of sedimentary organic material, many organic compounds have unknown or variable decomposition temperatures. Third, mixtures of organic compounds may result in significant chemistry within the pyrolysis reactor, prior to introduction of oxygen along the flow path. Gaussian decomposition of the reaction rate may be too simple to fully explain the combination of these factors. To relate both the radiocarbon age over different temperature intervals and the pyrolysis reaction thermograph (temperature (°C) vs. CO2 evolved (?mol)) obtained from PTP/CS to chemical composition of sedimentary organic material, we present a modeling framework developed based upon the ramped pyrolysis decomposition of simple mixtures of organic compounds (i.e. cellulose, lignin, plant fatty acids, etc.) often found in sedimentary organic material to account for changes in thermograph shape. The decompositions will be compositionally verified by 13C NMR analysis of pyrolysis residues from interrupted reactions. This will allow for constraint of decomposition temperatures of individual compounds as well as chemical reactions between volatilized moieties in mixtures of these compounds. We will apply this framework with 13C NMR analysis of interrupted pyrolysis residues and radiocarbon data from PTP/CS analysis of sedimentary organic material from a freshwater marsh wetland in Barataria Bay, Louisiana. We expect to characterize the bulk chemical composition during pyrolysis and as well as diagenetic changes with depth. Most importantly, we expect to constrain the potential and the limitations of this modeling framework for application to other depositional environments.
Molecular identification of organic compounds in atmospheric complex mixtures and relationship to atmospheric chemistry and sources.
Mazurek, Monica A
This article describes a chemical characterization approach for complex organic compound mixtures associated with fine atmospheric particles of diameters less than 2.5 m (PM2.5). It relates molecular- and bulk-level chemical characteristics of the complex mixture to atmospheric chemistry and to emission sources. Overall, the analytical approach describes the organic complex mixtures in terms of a chemical mass balance (CMB). Here, the complex mixture is related to a bulk elemental measurement (total carbon) and is broken down systematically into functional groups and molecular compositions. The CMB and molecular-level information can be used to understand the sources of the atmospheric fine particles through conversion of chromatographic data and by incorporation into receptor-based CMB models. Once described and quantified within a mass balance framework, the chemical profiles for aerosol organic matter can be applied to existing air quality issues. Examples include understanding health effects of PM2.5 and defining and controlling key sources of anthropogenic fine particles. Overall, the organic aerosol compositional data provide chemical information needed for effective PM2.5 management. PMID:12634131
Intrinsic charge trapping in organic and polymeric semiconductors: a physical chemistry perspective
Zhu, Xiaoyang; Barbara, Paul F.; Kaake, Loren
We aim to understand the origins of intrinsic charge carrier traps in organic and polymeric semiconductor materials from a physical chemistry perspective. In crystalline organic semiconductors, we point out some of the inadequacies in the description of intrinsic charge traps using language and concepts developed for inorganic semiconductors. In ?-conjugated polymeric semiconductors, we suggest the presence of a two-tier electronic energy landscape, a bimodal majority landscape due to two dominant structural motifs and a minority electronic energy landscape from intrinsic charged defects. The bimodal majority electronic energy landscape results from a combination of amorphous domains and microcrystalline or liquid-crystalline domains. The minority tier of the electronic density of states is comprised of deep Coulomb traps embedded in the majority electronic energy landscape. This minority electronic energy landscape may dominate transport properties at low charge carrier densities, such as those expected for organic photovoltaic devices, while the bimodal majority electronic energy landscape becomes significant at high carrier densities, that is, in organic field effect transistors.
ERIC Educational Resources Information Center
School Science Review, 1982
Presents background information, laboratory procedures, classroom materials/activities, and experiments for chemistry. Topics include superheavy elements, polarizing power and chemistry of alkali metals, particulate carbon from combustion, tips for the chemistry laboratory, interesting/colorful experiments, behavior of bismuth (III) iodine, and…
Introduction of water chemistry conditions of the secondary coolant circuit with metering organic amines at nuclear power stations equipped with VVER-1000 reactors
NASA Astrophysics Data System (ADS)
Tyapkov, V. F.; Erpyleva, S. F.; Bykova, V. V.
Results from introduction of new water chemistry conditions involving metering of organic amines (morpholine and ethanolamine) at nuclear power stations equipped with VVER-1000 reactors are presented.
Oxygenated Organic Chemicals in the Pacific Troposphere: Distribution, Sources and Chemistry
NASA Technical Reports Server (NTRS)
Singh, Hanwant B.; Salas, L.; Chatfield, R.; Czech, E.; Fried, A.; Evans, M.; Jacob, D. J.; Blake, D.; Heikes, B.; Talbot, R.
Airborne measurements of a large number of oxygenated organic chemicals (Oxorgs) were carried out in the Pacific troposphere (0.1-12 km) in the Spring of 2001 (Feb. 24-April 10). Specifically these measuremen ts included acetone, methylethyl ketone (MEK), methanol, ethanol, ace taldehyde, propionaldehyde, PANS, and organic nitrates. Complementary measurements of formaldehyde, organic peroxides, and tracers were al so available. Ox-orgs were abundant in the clean troposphere and were greatly enhanced in the outflow regions from Asia. Their mixing ratios were typically highest in the lower troposphere and declined toward s the upper troposphere and the lowermost stratosphere. Their total a bundance (Ox-orgs) significantly exceeded that of NMHC (C2-C8 NMHC). A comparison of these data with observations collected some seven yea rs earlier (Feb.-March, 1994), did not reveal any significant changes . Throughout the troposphere mixing ratios of Ox-orgs were strongly c orrelated with each other as well as with tracers of fossil and bioma sshiof'uel combustion. Analysis of the relative enhancement of selected Oxorgs with respect to CH3Cl and CO in twelve sampled plumes, origi nating from fires, is used to assess their primary and secondary sour ces from biomass combustion. The composition of these plumes also ind icates a large shift of reactive nitrogen into the PAN reservoir ther eby limiting ozone formation. The Harvard 3-D photochemical model, th at uses state of the art chemistry and source information, is used to compare simulated and observed mixing ratios of selected species. A 1 -D model is used to explore the chemistry of aldehydes. These results will be presented.
Laboratory studies of organic peroxy radical chemistry: an overview with emphasis on recent issues of atmospheric significance.
Orlando, John J; Tyndall, Geoffrey S
Organic peroxy radicals (often abbreviated RO(2)) play a central role in the chemistry of the Earth's lower atmosphere. Formed in the atmospheric oxidation of essentially every organic species emitted, their chemistry is part of the radical cycles that control the oxidative capacity of the atmosphere and lead to the formation of ozone, organic nitrates, organic acids, particulate matter and other so-called secondary pollutants. In this review, laboratory studies of this peroxy radical chemistry are detailed, as they pertain to the chemistry of the atmosphere. First, a brief discussion of methods used to detect the peroxy radicals in the laboratory is presented. Then, the basic reaction pathways - involving RO(2) unimolecular reactions and bimolecular reactions with atmospheric constituents such as NO, NO(2), NO(3), O(3), halogen oxides, HO(2), and other RO(2) species - are discussed. For each of these reaction pathways, basic reaction rates are presented, along with trends in reactivity with radical structure. Focus is placed on recent advances in detection methods and on recent advances in our understanding of radical cycling processes, particularly pertaining to the complex chemistry associated with the atmospheric oxidation of biogenic hydrocarbons. PMID:22847633
Development and analysis of educational technologies for a blended organic chemistry course
NASA Astrophysics Data System (ADS)
Evans, Michael James
Blended courses incorporate elements of both face-to-face and online instruction. The extent to which blended courses are conducted online, and the proper role of the online components of blended courses, have been debated and may vary. What can be said in general, however, is that online tools for blended courses are typically culled together from a variety of sources, are often very large scale, and may present distractions for students that decrease their utility as teaching tools. Furthermore, large-scale educational technologies may not be amenable to rigorous, detailed study, limiting evaluation of their effectiveness. Small-scale educational technologies run from the instructor's own server have the potential to mitigate many of these issues. Such tools give the instructor or researcher direct access to all available data, facilitating detailed analysis of student use. Code modification is simple and rapid if errors arise, since code is stored where the instructor can easily access it. Finally, the design of a small-scale tool can target a very specific application. With these ideas in mind, this work describes several projects aimed at exploring the use of small-scale, web-based software in a blended organic chemistry course. A number of activities were developed and evaluated using the Student Assessment of Learning Gains survey, and data from the activities were analyzed using quantitative methods of statistics and social network analysis methods. Findings from this work suggest that small-scale educational technologies provide significant learning benefits for students of organic chemistry---with the important caveat that instructors must offer appropriate levels of technical and pedagogical support for students. Most notably, students reported significant learning gains from activities that included collaborative learning supported by novel online tools. For the particular context of organic chemistry, which has a unique semantic language (Lewis structures), the incorporation of shared video was a novel but important element of these activities. In fields for which mere text would not provide enough information in communications between students, video offers an appealing medium for student-student interaction.
ERIC Educational Resources Information Center
School Science Review, 1976
Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)
The Organic Chemistry of Volcanoes: Case Studies at Cerro Negro, Nicaragua and Oldoinyo Lengai, Tanzania
NASA Astrophysics Data System (ADS)
Teague, A. J.; Seward, T. M.; Gize, A. P.; Hall, T.
Though it has long been known that volcanoes emit organic compounds within their fumarolic gases, it is only in recent years that a concerted attempt has been made to catalogue and quantify the species and fluxes. Two general lines of interest dominate this study. Firstly, volcanic gases represent some of the most likely environments in which the precursor molecules necessary for the origin of life were synthesised. The existence of an active, abiotic, organic chemistry in such settings today is fundamental to our understanding of the early Earth. Secondly, the presence of halogenated organic compounds is of interest to the atmospheric sciences, particularly with respect to their ozone depleting potential. It is clear that natural sources of halocarbons must exist, and though current natural fluxes are low with respect to the anthropogenic signature, volcanogenic halocarbons may have proved to be significant during the eruption of supervolcanoes and continental flood basalts. In this study, gases were collected from fumaroles in the craters of two, very different, active volcanoes. Cerro Negro, a young basaltic cinder cone belonging to the Central American Volcanic Belt, could be defined as a typical subduction zone volcano. Gases were collected from Cerro Negro during March 2003 and 2004 from a single fumarole discharging close to the crater floor. In contrast, Oldoinyo Lengai is the world's only active carbonatite volcano and represents the most extreme case of alkali volcanism in the East African Rift system. Fieldwork was conducted in the northern summit crater of Lengai over 8 days in October 2003. In this period, the volcano was in near continuous eruption and gases were sampled from two fumaroles situated within 20m of the eruptive centre, though measured gas temperatures were low at around 195°C. Organic compounds were collected using a variety of activated carbon, molecular sieve type adsorbents, packed into glass cartridges. The water and acid matrix of the gas was first removed using a pair of condensation flasks cooled in ice/water slush. The gas was then passed through the adsorbent cartridges using a low flow battery powered pump. The gases were analysed using GCMS techniques. At Oldoinyo Lengai a wide variety of simple biomolecules such as acetic acid, pyrole and ethanol is noted. However, the low gas temperatures imply that these compounds are the result of bacterial activity within the system rather than abiotic synthesis. At Cerro Negro a rich organic chemistry was found. Alkanes, alkenes and aromatics are present in significant concentrations up to C12. Additionally, halogenated compounds such as trichlorofluoromethane (CFC11), chlorobenzene and tetrachloroethene were discovered in concentrations of up to 10ppbv, permitting revised estimates of the global volcanogenic flux of such halocarbons.
Adsorption of amino acids and nucleic acid bases onto minerals: a few suggestions for prebiotic chemistry experiments
NASA Astrophysics Data System (ADS)
Zaia, Dimas A. M.
Amino acids and nucleic acid bases are very important for the living organisms. Thus, their protection from decomposition, selection, pre-concentration and formation of biopolymers are important issues for understanding the origin of life on the Earth. Minerals could have played all of these roles. This paper discusses several aspects involving the adsorption of amino acids and nucleic acid bases onto minerals under conditions that could have been found on the prebiotic Earth; in particular, we recommend the use of minerals, amino acids, nucleic acid bases and seawater ions in prebiotic chemistry experiments. Several experiments involving amino acids, nucleic acid bases, minerals and seawater ions are also suggested, including: (a) using well-characterized minerals and the standardization of the mineral synthesis methods; (b) using primary chondrite minerals (olivine, pyroxene, etc.) and clays modified with metals (Cu, Fe, Ni, Mo, Zn, etc.); (c) determination of the possible products of decomposition due to interactions of amino acids and nucleic acid bases with minerals; (d) using minerals with more organophilic characteristics; (e) using seawaters with different concentrations of ions (i.e. Na+, Ca2+, Mg2+, SO4 2- and Cl-) (f) using non-protein amino acids (AIB, ?-ABA, ?-ABA, ?-ABA and ?-Ala and g) using nucleic acid bases other than adenine, thymine, uracil and cytosine. These experiments could be useful to clarify the role played by minerals in the origin of life on the Earth.
Coupling Molecular Modeling to the Traditional "IR-ID" Exercise in the Introductory Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Stokes-Huby, Heather; Vitale, Dale E.
This exercise integrates the infrared unknown identification ("IR-ID") experiment common to most organic laboratory syllabi with computer molecular modeling. In this modification students are still required to identify unknown compounds from their IR spectra, but must additionally match some of the absorptions with computed frequencies they…
Synthesis and Hydrogenation of Disubstituted Chalcones: A Guided-Inquiry Organic Chemistry Project
ERIC Educational Resources Information Center
Mohrig, Jerry R.; Hammond, Christina Noring; Schatz, Paul F.; Davidson, Tammy A.
Guided-inquiry experiments offer the same opportunities to participate in the process of science as classical organic qualitative analysis used to do. This three-week guided-inquiry project involves an aldol-dehydration synthesis of a chalcone chosen from a set of nine, followed by a catalytic transfer hydrogenation reaction using ammonium formate…
Aerosol and cloud chemistry of amines from CCS - reactivity experiments and numerical modeling
NASA Astrophysics Data System (ADS)
Weller, Christian; Tilgner, Andreas; Herrmann, Hartmut
Capturing CO2 from the exhaust of power plants using amine scrubbing is a common technology. Therefore, amines can be released during the carbon capture process. To investigate the tropospheric chemical fate of amines from CO2 capturing processes and their oxidation products, the impact of aqueous aerosol particles and cloud droplets on the amine chemistry has been considered. Aqueous phase reactivity experiments of NO3 radicals and ozone with relevant amines and their corresponding nitrosamines were performed. Furthermore, nitrosamine formation and nitrosamine photolysis was investigated during laboratory experiments. These experiments implicated that aqueous phase photolysis can be an effective sink for nitrosamines and that ozone is unreactive towards amines and nitrosamines. Multiphase phase oxidation schemes of amines, nitrosamines and amides were developed, coupled to the existing multiphase chemistry mechanism CAPRAM and built into the Lagrangian parcel model SPACCIM using published and newly measured data. As a result, both deliquescent particles and cloud droplets are important compartments for the multiphase processing of amines and their products. Amines can be readily oxidised by OH radicals in the gas and cloud phase during daytime summer conditions. However, amine oxidation is restricted during winter conditions with low photochemical activity leading to long lifetimes of amines. The importance of the gas and aqueous phase depends strongly on the partitioning of the different amines. Furthermore, the simulations revealed that the aqueous formation of nitrosamines in aerosol particles and could droplets is not a relevant process under tropospheric conditions.
Ascorbic Acid as a Standard for Iodometric Titrations. An Analytical Experiment for General Chemistry
NASA Astrophysics Data System (ADS)
Silva, Cesar R.; Simoni, Jose A.; Collins, Carol H.; Volpe, Pedro L. O.
Ascorbic acid is suggested as the weighable compound for the standardization of iodine solutions in an analytical experiment in general chemistry. The experiment involves an iodometric titration in which iodine reacts with ascorbic acid, oxidizing it to dehydroascorbic acid. The redox titration endpoint is determined by the first iodine excess that is complexed with starch, giving a deep blue-violet color. The results of the titration of iodine solution using ascorbic acid as a calibration standard were compared with the results acquired by the classic method using a standardized solution of sodium thiosulfate. The standardization of the iodine solution using ascorbic acid was accurate and precise, with the advantages of saving time and avoiding mistakes due to solution preparation. The colorless ascorbic acid solution gives a very clear and sharp titration end point with starch. It was shown by thermogravimetric analysis that ascorbic acid can be dried at 393 K for 2 h without decomposition. This experiment allows general chemistry students to perform an iodometric titration during a single laboratory period, determining with precision the content of vitamin C in pharmaceutical formulations.
Synthesis of Well-Defined Copper "N"-Heterocyclic Carbene Complexes and Their Use as Catalysts for a "Click Reaction": A Multistep Experiment that Emphasizes the Role of Catalysis in Green Chemistry
ERIC Educational Resources Information Center
Ison, Elon A.; Ison, Ana
A multistep experiment for an advanced synthesis lab course that incorporates topics in organic-inorganic synthesis and catalysis and highlights green chemistry principles was developed. Students synthesized two "N"-heterocyclic carbene ligands, used them to prepare two well-defined copper(I) complexes and subsequently utilized the complexes as…
Distributed Pore Chemistry in Porous Organic Polymers in Tissue Culture Flasks
NASA Technical Reports Server (NTRS)
Koontz, Steven L. (Inventor)
A method for making a biocompatible polymer article using a uniform atomic oxygen treatment is disclose. The substrate may be subsequently optionally grated with a compatibilizing compound. Compatibilizing compounds may include proteins, phosphorylcholine groups, platelet adhesion preventing polymers, albumin adhesion promoters, and the like. The compatibilized substrate may also have a living cell layer adhered thereto. The atomic oxygen is preferably produced by a flowing afterglow microwave discharge, wherein the substrate resides in a sidearm out of the plasma. Also, methods for culturing cells for various purposes using the various membranes are disclosed as well. Also disclosed are porous organic polymers having a distributed pore chemistry (DPC) comprising hydrophilic and hydrophobic regions, and a method for making the DPC by exposing the polymer to atomic oxygen wherein the rate of hydrophilization is greater than the rate of mass loss.
Global tropospheric experiment at the Hong Kong Atmosphere Chemistry Measurement Station
NASA Technical Reports Server (NTRS)
Carroll, Mary Ann; Wang, Tao
The major activities of the Global Tropospheric Experiment at the Hong Kong Atmospheric Chemistry Measurement Station are presented for the period 1 January - 31 December 1995. Activities included data analysis, reduction, and archiving of atmospheric measurements and sampling. Sampling included O3, CO, SO2, NO, TSP, RSP, and ozone column density. A data archive was created for the surface meteorological data. Exploratory data analysis was performed, including examination of time series, frequency distributions, diurnal variations and correlation. The major results have been or will be published in scientific journals as well as presented at conferences/workshops. Abstracts are attached.
NSDL National Science Digital Library
Charnine, Michael
This compiled site contains titles and links to over 40 sites, journal articles, course and tutorial materials, simulations, batteries, and other resources. Definitions of chemistry, theoretical chemistry, organic, physical and nuclear chemistry are integrated with the links to outside materials. A number of useful keywords are included to help users navigate the materials.
Content-related interactions and methods of reasoning within self-initiated organic chemistry study groups
NASA Astrophysics Data System (ADS)
Christian, Karen Jeanne
Students often use study groups to prepare for class or exams; yet to date, we know very little about how these groups actually function. This study looked at the ways in which undergraduate organic chemistry students prepared for exams through self-initiated study groups. We sought to characterize the methods of social regulation, levels of content processing, and types of reasoning processes used by students within their groups. Our analysis showed that groups engaged in predominantly three types of interactions when discussing chemistry content: co-construction, teaching, and tutoring. Although each group engaged in each of these types of interactions at some point, their prevalence varied between groups and group members. Our analysis suggests that the types of interactions that were most common depended on the relative content knowledge of the group members as well as on the difficulty of the tasks in which they were engaged. Additionally, we were interested in characterizing the reasoning methods used by students within their study groups. We found that students used a combination of three content-relevant methods of reasoning: model-based reasoning, case-based reasoning, or rule-based reasoning, in conjunction with one chemically-irrelevant method of reasoning: symbol-based reasoning. The most common way for groups to reason was to use rules, whereas the least common way was for students to work from a model. In general, student reasoning correlated strongly to the subject matter to which students were paying attention, and was only weakly related to student interactions. Overall, results from this study may help instructors to construct appropriate tasks to guide what and how students study outside of the classroom. We found that students had a decidedly strategic approach in their study groups, relying heavily on material provided by their instructors, and using the reasoning strategies that resulted in the lowest levels of content processing. We suggest that instructors create more opportunities for students to explore model-based reasoning, and to create opportunities for students to be able to co-construct in a collaborative manner within the context of their organic chemistry course.
Fostering expert inquiry skills and beliefs about chemistry through the MORE laboratory experience
NASA Astrophysics Data System (ADS)
Tien, Lydia Tsing
Typical college science instruction fails to promote an accurate view of science as a discipline and a practice. This is likely due to the fact that the experiences of students in the classroom are very different from the actions and thought processes of scientists. Thus, students often leave the classroom experience with poor inquiry skills and naive beliefs about scientific practice. In order to bridge the gap between the typical classroom experience and expert practice, the MORE Project laboratory curriculum was developed to accompany the general chemistry course at the University of California at Berkeley. The framework guiding the curriculum development considered findings from educational and cognitive science research. The three components of the framework are: (a) exploration of concepts through authentic scientific inquiry; (b) promotion of metacognition; and (c) support for guided discovery. The curriculum provides students with a cognitive model of expert research, the MORE (Model-Observe-Reflect-Explain) Cycle, to encourage students to explore conceptually-rich systems through authentic research opportunities, such as designing experiments and refining explanatory models. By embedding the MORE structure into the laboratory curriculum, we provide students with a model for how scientists think through the inquiry process. In order to assess the impact of the MORE Project learning environment, it was implemented in two sections concurrent with the traditional laboratory experience. Various instruments were administered to determine any differences between the test and control groups with regards to attitudes towards chemistry, conceptual understanding, inquiry skills, and beliefs about scientific practice. Based on the analyses, students experiencing the MORE classroom achieved significant gains in all areas compared with students enrolled in the more traditional laboratory class. Specifically, students in the MORE class (a) recognized the complex, dynamic processes typical of scientific practice; (b) developed more sophisticated inquiry skills; and (c) practiced modeling and reflection in the laboratory.
Chemistry of organic carbon in soil with relationship to the global carbon cycle
Post, W.M. III (Oak Ridge National Lab., TN (USA))
Soil organic carbon in active exchange with the atmosphere constitutes approximately two-thirds of the carbon in terrestrial ecosystems. The large size and long residence time of this pool make it an important component of the global carbon cycle. The amount of carbon stored in soils and the rate of exchange of soil carbon with the atmosphere depends on many factors related to the chemistry of soil organic matter. The amount of carbon stored in soil is determined by the balance of two biotic processes associated with productivity of terrestrial vegetation and decomposition of organic matter. Each of these processes have strong physical controls that can be related to the climate variables temperature and precipitation at a regional or global scale. Soil carbon density generally increases with increasing precipitation, and there is an increase in soil carbon with decreasing temperature for any particular level of precipitation. Various ecosystem disturbances alter the balances between production and decomposition and therefore change the amount of carbon in soil. The most severe perturbation is conversion of natural vegetation to cultivation. The amount of soil carbon and nitrogen change resulting from cultivation depends on the initial amounts of each. Average changes in nitrogen are about one half to one forth the corresponding average carbon changes. Analysis of carbon and nitrogen linkages in soil shed some light on soil carbon dynamics after conversion to agriculture. The amount of initial carbon lost is associated with the amount of carbon in excess of C/N ratio of about 12 to 14. Soils with a high C/N ratio lose a larger fraction of the initial carbon then those with low C/N ratios. Soils with high C/N ratios have a larger percentage of organic matter in slowly decomposing forms. Cultivation results in a lowered input of slowly decomposing material which causes a reduction in overall carbon levels.
The Cyclohexanol Cycle and Synthesis of Nylon 6,6: Green Chemistry in the Undergraduate Organic Laboratory
ERIC Educational Resources Information Center
Dintzner, Matthew R.; Kinzie, Charles R.; Pulkrabek, Kimberly; Arena, Anthony F.
A one-term synthesis project that incorporates many of the principles of green chemistry is presented for the undergraduate organic laboratory. In this multistep scheme of reactions, students react, recycle, and ultimately convert cyclohexanol to nylon 6,6. The individual reactions in the project employ environmentally friendly methodologies, and…
Self-Regulated Learning Study Strategies and Academic Performance in Undergraduate Organic Chemistry: An Investigation Examining Ethnically Diverse Students
ERIC Educational Resources Information Center
Lopez, Enrique J.; Nandagopal, Kiruthiga; Shavelson, Richard J.; Szu, Evan; Penn, John
This study sought to identify ethnically diverse students' study strategies in organic chemistry and their relationships to course outcomes. Study diaries, concept maps, and problem sets were used to assess study outcomes. Findings show that students engage in four commonly used reviewing-type strategies, regardless of ethnic group…
Development and Implementation of a First-Semester Hybrid Organic Chemistry Course: Yielding Advantages for Educators and Students
ERIC Educational Resources Information Center
Ealy, Julie B.
A first-semester organic chemistry course was developed as a hybrid course. The students met face-to-face for one class each week (50 minutes) and the lectures were accessible online via Adobe Connect. Quizzes were scheduled for almost every lecture with access online through ANGEL. In addition, the students had three in-class tests and one final…
Gender Fair Efficacy of Concept Mapping Tests in Identifying Students' Difficulties in High School Organic Chemistry
ERIC Educational Resources Information Center
Gafoor, Kunnathodi Abdul; Shilna, V.
In view of the perceived difficulty of organic chemistry unit for high schools students, this study examined the usefulness of concept mapping as a testing device to assess students' difficulty in the select areas. Since many tests used for identifying students misconceptions and difficulties in school subjects are observed to favour one or…
Development and Assessment of a Diagnostic Tool to Identify Organic Chemistry Students' Alternative Conceptions Related to Acid Strength
ERIC Educational Resources Information Center
McClary, LaKeisha M.; Bretz, Stacey Lowery
The central goal of this study was to create a new diagnostic tool to identify organic chemistry students' alternative conceptions related to acid strength. Twenty years of research on secondary and college students' conceptions about acids and bases has shown that these important concepts are difficult for students to apply to qualitative problem…
PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Glycosynthase-based synthesis of xylo-oligosaccharides using an engineered
McIntosh, Lawrence P.
PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Glycosynthase-based synthesis of xylo-oligosaccharides of sugar acceptors using glycosyl fluoride donors to afford oligosaccharides without any enzymatic hydrolysis. Glycosynthase technology has proven fruitful for the facile synthesis of useful oligosaccharides
Examining the Impact of Student Use of Multiple Modal Representations in Constructing Arguments in Organic Chemistry Laboratory Classes
ERIC Educational Resources Information Center
Hand, Brian; Choi, Aeran
This study was designed to examine students' use of multiple modal representations within their written arguments as a consequence of completing a series of investigations of an organic chemistry laboratory course. One hundred and eleven students from a major Midwestern university were involved in using the Science Writing Heuristic (SWH) approach…
Preliminary analysis of LDEF instrument A0187-1: Chemistry of Micrometeoroids Experiment
NASA Technical Reports Server (NTRS)
Hoerz, Friedrich; Bernhard, Ronald P.; Warren, Jack; See, Thomas H.; Brownlee, Donald E.; Laurance, Mark R.; Messenger, Scott; Peterson, Robert B.
The Chemistry of Micrometeoroids Experiment (CME) exposed approximately 0.8 sq. m of gold on the Long Duration Exposure Facility's (LDEF's) trailing edge (location A03) and approximately 1.1 sq. m of aluminum in the forward-facing A11 location. The most significant results to date relate to the discovery of unmelted pyroxene and olivine fragments associated with natural cosmic dust impacts. The latter are sufficiently large for detailed phase studies, and they serve to demonstrate that recovery of unmelted dust fragments is a realistic prospect for further dust experiments that will employ more advanced collector media. We also discovered that man-made debris impacts occur on the LDEF's trailing edge with substantially higher frequency than expected, suggesting that orbital debris in highly elliptical orbits may have been somewhat underestimated.
Human development VIII: a theory of "deep" quantum chemistry and cell consciousness: quantum chemistry controls genes and biochemistry to give cells and higher organisms consciousness and complex behavior.
Ventegodt, Sřren; Hermansen, Tyge Dahl; Flensborg-Madsen, Trine; Nielsen, Maj Lyck; Merrick, Joav
Deep quantum chemistry is a theory of deeply structured quantum fields carrying the biological information of the cell, making it able to remember, intend, represent the inner and outer world for comparison, understand what it "sees", and make choices on its structure, form, behavior and division. We suggest that deep quantum chemistry gives the cell consciousness and all the qualities and abilities related to consciousness. We use geometric symbolism, which is a pre-mathematical and philosophical approach to problems that cannot yet be handled mathematically. Using Occam's razor we have started with the simplest model that works; we presume this to be a many-dimensional, spiral fractal. We suggest that all the electrons of the large biological molecules' orbitals make one huge "cell-orbital", which is structured according to the spiral fractal nature of quantum fields. Consciousness of single cells, multi cellular structures as e.g. organs, multi-cellular organisms and multi-individual colonies (like ants) and human societies can thus be explained by deep quantum chemistry. When biochemical activity is strictly controlled by the quantum-mechanical super-orbital of the cell, this orbital can deliver energetic quanta as biological information, distributed through many fractal levels of the cell to guide form and behavior of an individual single or a multi-cellular organism. The top level of information is the consciousness of the cell or organism, which controls all the biochemical processes. By this speculative work inspired by Penrose and Hameroff we hope to inspire other researchers to formulate more strict and mathematically correct hypothesis on the complex and coherence nature of matter, life and consciousness. PMID:17115084
Quantitative Measurement of Magnetic Hyperfine Parameters and the Physical Organic Chemistry of Supramolecular Systems
NASA Astrophysics Data System (ADS)
Bender, Christopher J.
The physical principles that underlie organic reactions were established by a systematic study of chemical reaction dynamics that employed correlated measurements of reaction rates and a physical parameter that could be related of the electronic properties of the molecules in question (Hammett, 1970). Today, molecular science emphasizes the concept of molecular device, which connotes a supramolecular structure (the term "supramolecule" loosely means a molecule that has multiple functionalities associated with it; for example, an enzyme might be regarded as a supramolecule in the sense that it features a supported metal catalyst and a receptor site that recognizes a specific substrate upon which the catalyst acts) that acts in some specific fashion. A molecular device may be biological (e.g., enzymes, contractile proteins; cf. Tanford & Reynolds, 2001), or it may be produced by synthetic means (e.g., molecular wires, switches, machines, etc.; cf. Sauvage, 2001; Balzani et al., 2003). Current synthetic chemistry provides the technical means that enable one to create and modify molecular devices so that structure may elicit some specific function, and so physical organic chemists are interested in reactions that involve engineered and structurally complex systems such as supported catalysts, protein active sites, or nanostructures (cf. amilton, 1996; Tidwell et al., 1997).
Drugs in the Chemistry Laboratory: The Conversion of Acetaminophen into Phenacetin.
ERIC Educational Resources Information Center
Volker, Eugene J.; And Others
Describes an experiment in which acetaminophen is converted into phenacetin, that has been used at Shepherd College in an introductory chemistry course for nurses and in the organic chemistry laboratory. (BT)
Electrochemistry of (Dihapto-Buckminster-Fullerene) Pentacarbonyl Tungsten(0): An Experiment for the Inorganic Chemistry Laboratory, Part III
ERIC Educational Resources Information Center
Igartua-Nieves, Elvin; Ocasio-Delgado, Yessenia; Rivera-Pagan, Jose; Cortes-Figueroa, Jose E.
Cyclic voltammetry experiments on [60]fullerene, (C[subscript 60]), and (dihapto-[60]fullerene) pentacarbonyl tungsten(0), ([eta][superscript 2]-C[subscript 60])W(CO)[subscript 5], constitute an educational experiment for the inorganic chemistry laboratory with a primary objective to teach the chemical interpretation of a voltammogram, in…
Characterization of High Explosives and Other Energetic Compounds by Computational Chemistry and Molecular Modeling: Experiments for Undergraduate Curriculum
ERIC Educational Resources Information Center
Bumpus, John A.; Lewis, Anne; Stotts, Corey; Cramer, Christopher J.
Experiments suited for the undergraduate instructional laboratory in which the heats of formation of several aliphatic and aromatic compounds are calculated, are described. The experiments could be used to introduce students to commercially available computational chemistry and its thermodynamics, while assess and compare the energy content of…
Determination of Spin-Lattice Relaxation of Time Using (Super 13)C NMR: An Undergraduate Physical Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
Gasyna, Zbigniew L.; Jurkiewicz, Antoni
An experiment designed for the physical chemistry laboratory where (super 13)C NMR is applied to determine the spin-lattice relaxation time for carbon atoms in n-hexanol is proposed. It is concluded that students learn the principles and concepts of NMR spectroscopy as well as dynamic NMR experiments.
Electronic Transitions as a Probe of Tetrahedral versus Octahedral Coordination in Nickel(II) Complexes: An Undergraduate Inorganic Chemistry Experiment.
ERIC Educational Resources Information Center
Filgueiras, Carlos A. L.; Carazza, Fernando
Discusses procedures, theoretical considerations, and results of an experiment involving the preparation of a tetrahedral nickel(II) complex and its transformation into an octahedral species. Suggests that fundamental aspects of coordination chemistry can be demonstrated by simple experiments performed in introductory level courses. (Author/JN)
Reaction Mechanisms for the Limited Reversibility of Li-O2 Chemistry in Organic Carbonate Electrolytes
Xu, Wu; Xu, Kang; Viswanathan, Vilayanur V.; Towne, Silas A.; Hardy, John S.; Xiao, Jie; Nie, Zimin; Hu, Dehong; Wang, Deyu; Zhang, Jiguang
The Li-O2 chemistry in nonaqueous carbonate electrolytes and the underneath reason of its limited reversibility was exhaustively investigated. The discharge products collected from the air cathode in a Li-O2 battery at different depth of discharge (DOD) were systematically analyzed with X-ray diffraction. It is revealed that, independent of the discharge depth, lithium alkylcarbonate (either lithium propylenedicarbonate - LPDC, or lithium ethylenedicarbonate - LEDC, with other related derivatives) and lithium carbonate (Li2CO3) are always the main products, obviously originated from the electrolyte solvents propylene carbonate (PC) and ethylene carbonate (EC). These lithium alkylcarbonates are obviously generated from the single-electron reductive decomposition of the corresponding carbonate solvents initiated by the attack of superoxide radical anions. On the other hand, neither lithium peroxide (Li2O2) nor lithium oxide (Li2O) is detected. More significantly, from in situ gas chromatography/mass spectroscopy it is found that Li2CO3 and Li2O cannot be oxidized even when charged up to 4.6 V vs. Li/Li+, while LPDC, LEDC and Li2O2 are readily able to, with CO2 and CO released with the re-oxidation of LPDC and LEDC. It is therefore concluded that the quasi-reversibility of Li-O2 chemistry observed hitherto in an organic carbonate-based electrolyte is actually reliant on the formation of lithium alkylcarbonates through the reductive decomposition of carbonate solvents during discharge process and the subsequent oxidation of these same alkylcarbonates during charge process. It is the poor oxidizability of these alkylcarbonate species that constitutes the obstruction to an ideal rechargeable Li-O2 battery.
Organic Chemistry in Interstellar Ices: Connection to the Comet Halley Results
NASA Technical Reports Server (NTRS)
Schutte, W. A.; Agarwal, V. K.; deGroot, M. S.; Greenberg, J. M.; McCain, P.; Ferris, J. P.; Briggs, R.
Mass spectroscopic measurements on the gas and dust in the coma of Comet Halley revealed the presence of considerable amounts of organic species. Greenberg (1973) proposed that prior to the formation of the comet UV processing of the ice mantles on grains in dense clouds could lead to the formation of complex organic molecules. Theoretical predictions of the internal UV field in dense clouds as well as the discovery in interstellar ices of species like OCS and OCN- which have been formed in simulation experiments by photoprocessing of interstellar ice analogues point to the importance of such processing. We undertook a laboratory simulation study of the formation of organic molecules in interstellar ices and their possible relevance to the Comet Halley results.
NSDL National Science Digital Library
Brooks, David W.
This website includes over 150 chemistry experiments in the following areas: Atomic Structure, Bonding, Chemical Reactions, Colligative Properties, Condensed States, Electrochemistry, Equilibrium Gases, Instrumentation, Limiting Reactant and more.
Chemistry Rocks: Redox Chemistry as a Geologic Tool.
ERIC Educational Resources Information Center
Burns, Mary Sue
Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)
Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments
Yin, Jun; Haggerty, Roy; Stoliker, Deborah L.; Kent, Douglas B.; Istok, Jonathan D.; Greskowiak, Janek; Zachara, John M.
In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity and low Ca concentrations (Columbia River water) enhanced adsorption and reduced aqueous concentrations. Conversely, high alkalinity and high Ca concentrations (Hanford groundwater) reduced adsorption and increased aqueous concentrations of U(VI). An equilibrium surface complexation model calibrated using laboratory batch experiments accounted for the decrease in U(VI) adsorption observed with increasing (bi)carbonate concentrations and other aqueous chemical conditions. In the column experiment, alternating pulses of river and groundwater caused swings in aqueous U(VI) concentration. A multispecies multirate surface complexation reactive transport model simulated most of the major U(VI) changes in two column experiments. The modeling results also indicated that U(VI) transport in the studied sediment could be simulated by using a single kinetic rate without loss of accuracy in the simulations. Moreover, the capability of the model to predict U(VI) transport in Hanford groundwater under transient chemical conditions depends significantly on the knowledge of real-time change of local groundwater chemistry.
A New Geoengineering Model Intercomparison Project (GeoMIP) Experiment Designed for Climate and Chemistry Models
Tilmes, S.; Mills, Mike; Niemeier, Ulrike; Schmidt, Hauke; Robock, Alan; Kravitz, Benjamin S.; Lamarque, J. F.; Pitari, G.; English, J. M.
A new Geoengineering Model Intercomparison Project (GeoMIP) experiment G4fAer (G4 fixed Aerosols) is proposed to investigate the impact of stratospheric aerosol geoengineering on atmospheric composition, climate, and the environment. In contrast to the earlier G4 GeoMIP experiment, which requires an injection of SO2 into the model, a prescribed aerosol forcing file is provided to the community, to be consistently applied to future model experiments between 2020 and 2100. This stratospheric aerosol distribution has been derived using the ECHAM HAM micro-physical model, based on an annual tropical injection of 8 Tg SO2 between 2020 and 2070. The performance of this experiment using climate and chemistry models in a multi-model comparison framework will allow us to answer scientific questions that have not been addressed in currently existing studies. A better understanding of the impact of geoengineering and the potential abrupt termination on climate and composition of the atmosphere in a changing environment is expected.
Secondary organic aerosol production from diesel vehicle exhaust: impact of aftertreatment, fuel chemistry and driving cycle
NASA Astrophysics Data System (ADS)
Gordon, T. D.; Presto, A. A.; Nguyen, N. T.; Robertson, W. H.; Na, K.; Sahay, K. N.; Zhang, M.; Maddox, C.; Rieger, P.; Chattopadhyay, S.; Maldonado, H.; Maricq, M. M.; Robinson, A. L.
Environmental chamber ("smog chamber") experiments were conducted to investigate secondary organic aerosol (SOA) production from dilute emissions from two medium-duty diesel vehicles (MDDVs) and three heavy-duty diesel vehicles (HDDVs) under urban-like conditions. Some of the vehicles were equipped with emission control aftertreatment devices, including diesel particulate filters (DPFs), selective catalytic reduction (SCR) and diesel oxidation catalysts (DOCs). Experiments were also performed with different fuels (100% biodiesel and low-, medium- or high-aromatic ultralow sulfur diesel) and driving cycles (Unified Cycle,~Urban Dynamometer Driving Schedule, and creep + idle). During normal operation, vehicles with a catalyzed DPF emitted very little primary particulate matter (PM). Furthermore, photooxidation of dilute emissions from these vehicles produced essentially no SOA (below detection limit). However, significant primary PM emissions and SOA production were measured during active DPF regeneration experiments. Nevertheless, under reasonable assumptions about DPF regeneration frequency, the contribution of regeneration emissions to the total vehicle emissions is negligible, reducing PM trapping efficiency by less than 2%. Therefore, catalyzed DPFs appear to be very effective in reducing both primary PM emissions and SOA production from diesel vehicles. For both MDDVs and HDDVs without aftertreatment substantial SOA formed in the smog chamber - with the emissions from some vehicles generating twice as much SOA as primary organic aerosol after 3 h of oxidation at typical urban VOC / NOx ratios (3 : 1). Comprehensive organic gas speciation was performed on these emissions, but less than half of the measured SOA could be explained by traditional (speciated) SOA precursors. The remainder presumably originates from the large fraction (~30%) of the nonmethane organic gas emissions that could not be speciated using traditional one-dimensional gas chromatography. The unspeciated organics - likely comprising less volatile species such as intermediate volatility organic compounds - appear to be important SOA precursors; we estimate that the effective SOA yield (defined as the ratio of SOA mass to reacted precursor mass) was 9 ± 6% if both speciated SOA precursors and unspeciated organics are included in the analysis. SOA production from creep + idle operation was 3-4 times larger than SOA production from the same vehicle operated over the Urban Dynamometer Driving Schedule (UDDS). Fuel properties had little or no effect on primary PM emissions or SOA formation.
The Mars Environmental Compatibility Assessment (MECA) Wet Chemistry Experiment on the Mars 2001 Lander
NASA Technical Reports Server (NTRS)
Grannan, S. M.; Meloy, T. P.; Hecht, H.; Anderson, M. S.; Buehler, M.; Frant, M.; Kounaves, S. P.; Manatt, K. S.; Pike, W. T.; Schubert, W.
The Mars Environmental Compatibility Assessment (MECA) is an instrument suite that will fly on the Mars Surveyor 2001 Lander Spacecraft. MECA is sponsored by the Human Exploration and Development of Space (HEDS) program and will evaluate potential hazards that the dust and soil of Mars might present to astronauts and their equipment on a future human mission to Mars. Four elements constitute the integrated MECA payload: a microscopy station, patch plates, an electrometer, and the wet chemistry experiment (WCE). The WCE is the first application of electrochemical sensors to study soil chemistry on another planetary body, in addition to being the first measurement of soil/water solution properties on Mars. The chemical composition and properties of the watersoluble materials present in the Martian soil are of considerable interest to the planetary science community because characteristic salts are formed by the water-based weathering of rocks, the action of volcanic gases, and biological activity. Thus the characterization of water-soluble soil materials on Mars can provide information on the geochemical history of the planet surface. Additional information is contained in the original extended abstract.
Organ procurement: experience from a southern Italian region.
Roncone, A; Vantaggiato, M D; Benvenuto, A; Nino, A; Iannello, A; De Giacomo, E; Verre, P; Formisani, P; Milano, G A; Burza, F; Caporale, S; Cirillo, S; Bonofiglio, R; Risoli, V; Petrassi, A
The authors report their experience of organ procurement during the last 5 years to evaluate a program that began in 1988 to improve organ retrieval in Calabria. In this region only two donations were reported up to 1988, one each in 1980 and 1985. Because of the large population on dialysis and the willingness of a group of surgeons and anesthesiologists, this program was undertaken in 1988 under the supervision of C.C.S.T. (Co-ordination of Centre and South Italy for Transplantation). This program was designed to act on two levels: to create a large group of people directly involved in health care (physicians and nurses) motivated in organ procurement and transplantation, and to diffuse the "culture" of organ donation among lay people. This was achieved by means of scientific meetings inside the hospital and with conventions and TV programs, supported by an Association of Volunteers, where ethical and scientific problems of organ donation and transplantation were discussed in simple language. Various meetings were also held with high school students. During these meetings a questionnaire was distributed among students. Results of this questionnaire show that the main obstacles to organ donation are the "unclear" concept of "brain death" and religious feelings, but after the concept of brain death was explained, a significant number of students showed a different attitude toward organ procurement and transplantation. Results of this program are extremely encouraging (23 organ donations during the last 3 years). We hope to improve our results in the near future, and we do believe that a further and significant increase to our preliminary good results could be achieved by the possibility of performing at least kidney transplantation in our institution. PMID:8644199
Carbon cycling and phytoplankton responses within highly-replicated shipboard carbonate chemistry manipulation experiments conducted around Northwest European Shelf Seas
NASA Astrophysics Data System (ADS)
Richier, S.; Achterberg, E. P.; Dumousseaud, C.; Poulton, A. J.; Suggett, D. J.; Tyrrell, T.; Zubkov, M. V.; Moore, C. M.
The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which in part likely reflects inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series of highly replicated (n = 8), short term (2-4 days) multi-level (? 4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically different experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterized by a suppression of net growth for small sized cells (< 10 ?m), were observed in the majority of the experiments, irrespective of nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasize how biological-chemical feedbacks may be altered in the future ocean.
Measurement of Henry's Law Constants Using Internal Standards: A Quantitative GC Experiment for the Instrumental Analysis or Environmental Chemistry Laboratory
ERIC Educational Resources Information Center
Ji, Chang; Boisvert, Susanne M.; Arida, Ann-Marie C.; Day, Shannon E.
An internal standard method applicable to undergraduate instrumental analysis or environmental chemistry laboratory has been designed and tested to determine the Henry's law constants for a series of alkyl nitriles. In this method, a mixture of the analytes and an internal standard is prepared and used to make a standard solution (organic solvent)…
Determination of Molecular Self-Diffusion Coefficients Using Pulsed-Field-Gradient NMR: An Experiment for Undergraduate Physical Chemistry Laboratory
ERIC Educational Resources Information Center
Harmon, Jennifer; Coffman, Cierra; Villarrial, Spring; Chabolla, Steven; Heisel, Kurt A.; Krishnan, Viswanathan V.
NMR spectroscopy has become one of the primary tools that chemists utilize to characterize a range of chemical species in the solution phase, from small organic molecules to medium-sized proteins. A discussion of NMR spectroscopy is an essential component of physical and biophysical chemistry lecture courses, and a number of instructional…
Heterogeneous chemistry of glyoxal on acidic solutions. An oligomerization pathway for secondary organic aerosol formation.
Gomez, Mario E; Lin, Yun; Guo, Song; Zhang, Renyi
The heterogeneous chemistry of glyoxal on sulfuric acid surfaces has been investigated at various acid concentrations and temperatures, utilizing a low-pressure fast flow laminar reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS). The uptake coefficient (?) of glyoxal ranges from (1.2 ± 0.06) × 10(-2) to (2.5 ± 0.01) × 10(-3) for 60-93 wt % H2SO4 at 253-273 K. The effective Henry's Law constant (H*) ranges from (98.9 ± 4.9) × 10(5) to (1.6 ± 0.1) × 10(5) M atm(-1) for 60-93 wt % at 263-273 K. Both the uptake coefficient and Henry's Law constant increase with decreasing acid concentration and temperature. Our results reveal a reaction mechanism of hydration followed by oligomerization for glyoxal on acidic media, indicating an efficient aqueous reaction of glyoxal on hygroscopic particles leading to secondary organic aerosol formation. PMID:25369518
The Space Environment Viability of Organics (SEVO) Experiment on the Organisms\\/Organics Exposure to Orbital Stresses (O\\/OREOS) Nanosatellite Mission
R. Quinn; P. Ehrenfreund; A. Mattioda; A. Ricco; N. Bramall; K. Bryson; J. Chittenden; C. Conley
The organism\\/organic exposure to orbital stresses nanosatellite has been developed as the first flight mission of the NASA Astrobiology Small-Payloads Program. The satellite includes the SEVO experiment, which investigates the stability of organics.
Evaluation of the MOCAGE Chemistry Transport Model during the ICARTT/ITOP Experiment
NASA Technical Reports Server (NTRS)
Bousserez, N.; Attie, J. L.; Peuch, V. H.; Michou, M.; Pfister, G.; Edwards, D.; Emmons, L.; Arnold, S.; Heckel, A.; Richter, A.; Shlager, H.; Lewis A.; Avery, M.; Sachse, G.; Browell, E.; Ferrare, R.
We evaluate the Meteo-France global chemistry transport 3D model MOCAGE (MOdele de Chimie Atmospherique a Grande Echelle) using the important set of aircraft measurements collected during the ICARRT/ITOP experiment. This experiment took place between US and Europe during summer 2004 (July 15-August 15). Four aircraft were involved in this experiment providing a wealth of chemical data in a large area including the North East of US and western Europe. The model outputs are compared to the following species of which concentration is measured by the aircraft: OH, H2O2, CO, NO, NO2, PAN, HNO3, isoprene, ethane, HCHO and O3. Moreover, to complete this evaluation at larger scale, we used also satellite data such as SCIAMACHY NO2 and MOPITT CO. Interestingly, the comprehensive dataset allowed us to evaluate separately the model representation of emissions, transport and chemical processes. Using a daily emission source of biomass burning, we obtain a very good agreement for CO while the evaluation of NO2 points out incertainties resulting from inaccurate ratio of emission factors of NOx/CO. Moreover, the chemical behavior of O3 is satisfactory as discussed in the paper.
A Green Starting Material for Electrophilic Aromatic Substitution for the Undergraduate Organic Laboratory
ERIC Educational Resources Information Center
Jones-Wilson, T. Michelle; Burtch, Elizabeth A.
Electrophilic aromatic substitution (EAS) experiment is designed for the second-semester and undergraduate organic chemistry laboratory. In the EAS experiment, the principles of green chemistry are discussed and illustrated in conjunction with the presentation of electrophilic aromatic substitution.
Understanding the Motivation and Help-Seeking Experiences of Adult, Online Chemistry Students
ERIC Educational Resources Information Center
Bannier, Betsy J.
The purpose of this study was to identify and explain factors that motivate and assist adult, online chemistry students to both enroll and persist in successfully completing general chemistry. Secondarily, the study sought to identify aspects of the online education process that are most challenging for adult, online chemistry students. Using a…
The Chemistry of Fitness. Active Activities.
ERIC Educational Resources Information Center
Bergandine, David R.; And Others
The outline for a unit on the chemistry of fitness and nutrition is presented. Topics discussed include the organic basis of life, functional groups, kitchen experiments, micronutrients, energetics, fitness vs. fatness, current topics, and evaluation. This unit reviews the basic concepts of chemical bonding, acid-base chemistry, stoichiometry, and…
Chemistry of carbon nanomaterials: Uses of lithium nanotube salts in organic syntheses and functionalization of graphite
NASA Astrophysics Data System (ADS)
Chattopadhyay, Jayanta
The effective utilization of carbon nanomaterials, such as single-walled carbon nanotubes (SWNTs) and graphite, has been hindered due to difficulties (poor solubility, poly-dispersity) in processing. Therefore, a high degree of sidewall functionalization, either covalent or non-covalent, is often required to overcome these difficulties as the functionalized nanomaterials exhibit better solubility (either in organic solvents or in water), dispersity, manipulation, and processibility. This thesis presents a series of convenient and efficient organic synthetic routes to functionalize carbon nanomaterials. Carbon nanotube salts, prepared by treating SWNTs with lithium in liquid ammonia, react readily with aryl halides to yield aryl-functionalized SWNTs. These arylated SWNTs are soluble in methanol and water upon treatment with oleum. Similarly, SWNTs can be covalently functionalized by different heteroatoms (nitrogen, oxygen, and sulfur). Using the reductive alkylation approach, a synthetic scheme is designed to prepare long chain carboxylic acid functionalized SWNTs [SWNTs-(RCOOH)] that can react with (1) amine-terminated polyethylene glycol (PEG) chains to yield water-soluble biocompatible PEGylated SWNTs that are likely to be useful in a variety of biomedical applications; (2) polyethyleneimine (PEI) to prepare a SWNTs-PEI based adsorbent material that shows a four-fold improvement in the adsorption capacity of carbon dioxide over commonly used materials, making it useful for regenerable carbon dioxide removal in spaceflight; (3) chemically modified SWNTs-(RCOOH) to permit covalent bonding to the nylon matrix, thus allowing the formation of nylon 6,10 and nylon 6,10/SWNTs-(RCOOH) nanocomposites. Furthermore, we find that the lithium salts of carbon nanotubes serve as a source of electrons to induce polymerization of simple alkenes and alkynes onto the surface of carbon nanotubes. In the presence of sulfide/disulfide bonds, SWNT salts can initiate the single electron transfer (SET) mechanism to functionalize carbon nanotubes with different alkyl/aryl groups. Using the reductive alkylation approach, we can also functionalize graphites by alkyl/carboxylic acid groups, making graphite soluble in organic solvents and water. Tailoring of graphite layers is also accomplished by using different metals in liquid ammonia. Finally, SWNT-epoxides/graphite epoxides are synthesized using m-CPBA. Quantification of the epoxide substituents on the nanotube/graphite surface is evaluated through the catalytic de-epoxidation reaction using MeReO 3/PPh3 as heterogeneous catalyst. In summary, the proposed covalent functionalization methods yield derivatized nanomaterials that can provide a solid platform for a number of exciting applications, ranging from material science to biomedical devices. Furthermore, the results presented in this thesis provide insight into the molecular chemistry at nano-resolution.
The Quantitative Resolution of a Mixture of Group II Metal Ions by Thermometric Titration with EDTA. An Analytical Chemistry Experiment.
ERIC Educational Resources Information Center
Smith, Robert L.; Popham, Ronald E.
Presents an experiment in thermometric titration used in an analytic chemistry-chemical instrumentation course, consisting of two titrations, one a mixture of calcium and magnesium, the other of calcium, magnesium, and barium ions. Provides equipment and solutions list/specifications, graphs, and discussion of results. (JM)
A Guided Inquiry Experiment for the Measurement of Activation Energies in the Biophysical Chemistry Laboratory: Decarboxylation of Pyrrole-2-Carboxylate
ERIC Educational Resources Information Center
Hutchinson, Kelly M.; Bretz, Stacey Lowery; Mettee, Howard D.; Smiley, Jeffrey A.
A laboratory experiment for undergraduate biophysical chemistry is described, in which the acid concentration and temperature dependences of the decarboxylation of pyrrole-2-carboxylate are measured using a continuous ultraviolet (UV) spectrophotometric assay. Data collection and analysis are structured using principles of guided inquiry. Data…
Ionic Strength Effect on the Rate of Reduction of Hexacyanoferrate (III) by Ascorbic Acid: A Physical Chemistry Laboratory Experiment.
ERIC Educational Resources Information Center
Watkins, Kenneth W.; Olson, June A.
Describes a physical chemistry experiment that allows students to test the effect of ionic strength on the rates of a reaction between ions. The reduction of hexacyanoferrate III by ascorbic acid is detailed. Comparisons with the iodine clock reaction are made. (CS)
Utilization of a Microcomputer for the Study of an Iodine Oxidation and Equilibrium Reaction: A Physical Chemistry Experiment.
ERIC Educational Resources Information Center
Julien, L. M.
Describes a physical chemistry experiment which incorporates the use of a microcomputer to enhance understanding of combined kinetic and equilibrium phenomena, to increase experimental capabilities when working with large numbers of students and limited equipment, and for the student to develop a better understanding of experimental design. (JN)
iPads in the Science Laboratory: Experience in Designing and Implementing a Paperless Chemistry Laboratory Course
ERIC Educational Resources Information Center
Hesser, Tiffany L.; Schwartz, Pauline M.
In the fall of 2012, 20 General Chemistry Honors students at the University of New Haven were issued the new iPad 3 to incorporate these devices both in the classroom and the laboratory. This paper will focus on the integration of the iPad into the laboratory curriculum while creating a paperless experience, an environment where no paper would…
Observation and Analysis of N[subscript 2]O Rotation-Vibration Spectra: A Physical Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
Bryant, Mark S.; Reeve, Scott W.; Burns, William A.
The linear molecule N[subscript 2]O is presented as an alternative gas-phase species for the ubiquitous undergraduate physical chemistry rotation-vibration spectroscopy experiment. Utilizing a 0.5 cm[superscript -1] resolution teaching grade FTIR spectrometer, 15 vibrational bands, corresponding to 1229 rotation-vibration transitions, have been…
Sol-Gel Synthesis of a Biotemplated Inorganic Photocatalyst: A Simple Experiment for Introducing Undergraduate Students to Materials Chemistry
ERIC Educational Resources Information Center
Boffa, Vittorio; Yue, Yuanzheng; He, Wen
As part of a laboratory course, undergraduate students were asked to use baker's yeast cells as biotemplate in preparing TiO[subscript 2] powders and to test the photocatalytic activity of the resulting materials. This laboratory experience, selected because of the important environmental implications of soft chemistry and photocatalysis, provides…
Preparation and Reactions of the 1,1-Dithiolato Complexes of Ni(II). An Undergraduate Coordination Chemistry Experiment.
ERIC Educational Resources Information Center
Ballester, L.; Perpinan, M. F.
Described is an undergraduate coordination chemistry experiment that enables students to relate concepts developed in class about the stereochemistry and coordination numbers to the interpretation of the electronic and infrared spectra and their magnetic behavior. Indicates that thermal decomposition and x-ray diffraction studies can also be…
Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment
ERIC Educational Resources Information Center
Najarian, Maya L.; Chinni, Rosemarie C.
This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…
Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment
ERIC Educational Resources Information Center
Xu, Xinhua; Wang, Xiaogang; Wu, Meifen
The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…
Removal of Aromatic Pollutant Surrogate from Water by Recyclable Magnetite-Activated Carbon Nanocomposite: An Experiment for General Chemistry
ERIC Educational Resources Information Center
Furlan, Ping Y.; Melcer, Michael E.
A general chemistry laboratory experiment using readily available chemicals is described to introduce college students to an exciting class of nanocomposite materials. In a one-step room temperature synthetic process, magnetite nanoparticles are embedded onto activated carbon matrix. The resultant nanocomposite has been shown to combine the…
A Simple Experiment in the Separation of a Solid-Phase Mixture and Infrared Spectroscopy for Introductory Chemistry
ERIC Educational Resources Information Center
Szalay, Paul S.
This experiment was developed as a means of incorporating instrumental analyses into an introductory chemistry laboratory. A two-component solid mixture of caffeine and ibuprofen is separated through a series of solution extractions and precipitation and their relative amounts measured. These compounds were chosen because the combination of…
Modeling SOA formation from alkanes and alkenes in chamber experiments: effect of gas/wall partitioning of organic vapors.
NASA Astrophysics Data System (ADS)
Stéphanie La, Yuyi; Camredon, Marie; Ziemann, Paul; Ouzebidour, Farida; Valorso, Richard; Madronich, Sasha; Lee-Taylor, Julia; Hodzic, Alma; Aumont, Bernard
Oxidation products of Intermediate Volatility Organic Compounds (IVOC) are expected to be the major precursors of secondary organic aerosols (SOA). Laboratory experiments were conducted this last decade in the Riverside APRC chamber to study IVOC oxidative mechanisms and SOA formation processes for a large set of linear, branched and cyclic aliphatic hydrocarbons (Ziemann, 2011). This dataset are used here to assess the explicit oxidation model GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere) (Aumont et al., 2005). The simulated SOA yields agree with the general trends observed in the chamber experiments. They are (i) increasing with the increasing carbon number; (ii) decreasing with increasing methyl branch number; and (iii) increasing for cyclic compounds compared to their corresponding linear analogues. However, simulated SOA yields are systematically overestimated regardless of the precursors, suggesting missing processes in the model. In this study, we assess whether gas-to-wall partitioning of organic vapors can explain these model/observation mismatches (Matsunaga and Ziemann, 2010). First results show that GECKO-A outputs better match the observations when wall uptake of organic vapors is taken into account. Effects of gas/wall partitioning on SOA yields and composition will be presented. Preliminary results suggest that wall uptake is a major process influencing SOA production in the Teflon chambers. References Aumont, B., Szopa, S., Madronich, S.: Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach. Atmos.Chem.Phys., 5, 2497-2517 (2005). P. J. Ziemann: Effects of molecular structure on the chemistry of aerosol formation from the OH-radical-initiated oxidation of alkanes and alkenes, Int. Rev.Phys.Chem., 30:2, 161-195 (2011). Matsunaga, A., Ziemann, P. J.: Gas-wall partitioning of organic compounds in a Teflon film chamber and potential effects on reaction product and aerosol yield measurements, Aerosol Sci. Technol., 44:10, 881-892 (2010).
Reprinted from The Journal of Organic Chemistry, 1991,Yol. 56. Copyright @ 1991by the American Chemical Society and reprinted by permissionof the copyright owner.
Prentiss, Mara
Reprinted from The Journal of Organic Chemistry, 1991,Yol. 56. Copyright @ 1991by the American) Sharon, N. Complex Carbohydrates, Their Chemistry, Biosyn- thesis and Function; Addison-Wesley: Reading is calculated on the basis of unreacted 1. dynamically favorable.T For preparation of sugar 1- phosphatesother
Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation
NASA Astrophysics Data System (ADS)
Chan, A. W. H.; Chan, M. N.; Surratt, J. D.; Chhabra, P. S.; Loza, C. L.; Crounse, J. D.; Yee, L. D.; Flagan, R. C.; Wennberg, P. O.; Seinfeld, J. H.
Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene), the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA) via methacrolein (a C4-unsaturated aldehyde) under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN) as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other ?, ?-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are ?, ?-unsaturated and contain an additional methyl group on the ?-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232) is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(O)OONO2) formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios (3-8), the SOA yields from isoprene high-NOx photooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of ?, ?-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.
Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation
NASA Astrophysics Data System (ADS)
Chan, A. W. H.; Chan, M. N.; Surratt, J. D.; Chhabra, P. S.; Loza, C. L.; Crounse, J. D.; Yee, L. D.; Flagan, R. C.; Wennberg, P. O.; Seinfeld, J. H.
Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene), the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA) via methacrolein (a C4-unsaturated aldehyde) under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN) as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other ?, ?-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are ?, ?-unsaturated and contain an additional methyl group on the ?-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232) is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(O)OONO2) formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios, the SOA yields from isoprene high-NOxphotooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of ?, ?-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.
Chemistry in an inorganic-organic hybrid aerogel: Chitosan-silica aerogel
NASA Astrophysics Data System (ADS)
Liu, Xipeng
In this thesis, chemistry in a nanoporous inorganic-organic hybrid aerogel (X-silica aerogel) has been explored. The aerogel typically consisted of 10%w/w bioderived polymer (chitosan), and 90%w/w inorganic silica, which interact at the molecule level. The aerogel has a low density in the range of 0.2--0.3 g/cm3, high surface area in the range of 500--950m 2/g, and large pore volume about 90%. The pores are about 3--5 nm in diameter and the size of the primary particles comprising the aerogel network is about 1.5nm. Chemical studies of X-silica aerogels were carried out in the first instance with organic molecules, including dansyl chloride (DC), succinic anhydride (SA), bis(4-isocynatocyclohexyl) methane (HMDI), and isocyanatoethyl methacrylate (IEMA). These reactions lead to modified X-silica aerogel products imparted with valuable functionalities, including fluorescence, carboxylic acid groups, and pendant isocyanate and methacrylate groups. The functionalized aerogels then were utilized to form novel composites. The isocyanate functionalized aerogels were combined with amine-containing silicone polymers to produce aerogel-silicone polymer composites, and methacrylate functionalized aerogels were reacted with hydroxyethylmethacrylate (HEMA) monomer to produce aerogel-polyHEMA composites. The chemical studies were extended to gold-ion Au(III)-X-silica aerogels. Photoreduction of the Au(IIl)-X-silica aerogels by UV irradiation at 254nm reduced the Au(III) ions into Au(0) nanoparticles (AuNPs) while oxidizing the chitosan. Various sizes of AuNPs, with mean diameters from 8--87nm were obtained by varying the Au(III) ions concentration in aerogels from Au(III)/-NH 2 (-NH2 amine groups on chitosan) ratio 1:120 to 1:5. The intensity and time of exposure to the UV light were varied to explore their effect. Two dimensional patterns of Au(0)-X-silica aerogels were achieved by UV irradiation through a mask. Photo-reduction of Au(III)-X-silica aerogels in the presence of various thiols and disulfides leads to functionalized Au nanoparticles by the strong chemisorption of sulfurs and Au nanoparticles. Moreover, when these are present during the photolysis they control the growth of the gold nanoparticles.
An overview of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx)
NASA Astrophysics Data System (ADS)
Dulac, François
The Chemistry-Aerosol Mediterranean Experiment (ChArMEx, http://charmex.lsce.ipsl.fr) is a French initiative of the MISTRALS meta-programme (Mediterranean Integrated Studies at Regional And Locals Scales, http://www.mistrals-home.org). It federates a great number of national and international cooperative research actions aiming at a scientific assessment of the present and future state of the atmospheric environment in the Mediterranean Basin, and of its impacts on the regional climate, air quality, and marine biogeochemistry. The target is short-lived particulate and gaseous tropospheric trace species which are the cause of poor air quality events, have two-way interactions with climate, or impact the marine biogeochemistry, in a context of strong regional anthropogenic and climatic pressures. The six ChArMEx work packages include Emissions, Chemical processes and ageing, Transport processes and air quality, Aerosol-radiation-climate interactions, Deposition, and Present and future variability and trends. For several years, efforts have been deployed in several countries to develop (i) a network of relevant stations for atmospheric chemistry at background sites on islands and continental coasts around the basin and (ii) several intensive field campaigns including the operation of surface supersites and various instrumented mobile platforms (large and ultra-light aircraft, sounding and drifting balloons, ZeroCO2 sailboat). This presentation is an attempt to provide an overview of the various experimental, remote sensing and modelling efforts produced and to highlight major findings, by referencing more detailed ChArMEx presentations given in this conference and recently published or submitted papers. During the first phase of the project experimental efforts have been mainly concentrated on the western basin. Plans for the 2nd phase of ChArMEx, more dedicated towards the eastern basin, will also be given. In particular we plan to develop monitoring activities at Cyprus and put more emphasis (i) on aerosol-cloud interactions in cooperation with the FP7/Environment project BACCHUS, (ii) the budget and transport of anthropogenic emissions from megacities, and (iii) processes at the air-sea interface with a proposal for a 1-month oceanographic cruise during a period of dust deposition events, joint with the biogeochemistry component of MISTRALS (project MERMEX: the Marine Ecosystem Response Mediterranean Experiment). Acknowledgements: ChArMEx activities involve about 50 institutes. FD expresses his gratitude to every contributing scientist. ChArMEx is supported by too many agencies for listing them all here. The main overall effort is from France, with ADEME, ANR, CNES, CNRS-INSU, the Collectivité Territoriale de Corse (incl. EU-FEDER funds), Météo-France, CEA and Ecole des Mines de Douai as the main funding agencies.
The ORGANIC Experiment on EXPOSE-R on the ISS: A Space Exposure Experiment
NASA Astrophysics Data System (ADS)
Bryson, Kathryn; Peeters, Z.; Salama, F.; Foing, B.; Ehrenfreund, P.; Ricco, A. J.; Jessberger, E.; Bischoff, A.; Breitfellner, M.; Schmidt, W.; Robert, F.
Aromatic networks are among the most abundant organic material in space. PAHs and fullerenes have been identified in meteorites and are thought to be among the carriers for numerous astronomical absorption and emission features. Thin films of selected PAHs and fullerenes have been subjected to the low Earth orbit environment as part of the ORGANIC experiment on the multi-user facility EXPOSE-R onboard the International Space Station. The ORGANIC experiment monitored the chemical evolution, survival, destruction, and chemical modification of the samples in space environment. EXPOSE-R with its experiment inserts was mounted on the outside of the ISS from March 10, 2009 to January 21, 2011. The samples were returned to Earth and inspected in spring 2011. The 682-day period outside the ISS provided continuous exposure to the cosmic-, solar-, and trapped-particle radiation background and >2500 h of unshadowed solar illumination. All trays carry both solar-irradiation-exposed and dark samples shielded from the UV photons, enabling discrimination between the effects of exposure to solar photons and cosmic rays. The samples were analyzed before exposure to the space environment with UV-VIS spectroscopy. Ground truth monitoring of additional sample carriers was performed through UV-VIS spectroscopy at regular intervals at NASA Ames Research Center. During the exposure on the ISS, two control sample carriers were exposed with a slight time shift in a planetary simulation chamber at the Microgravity User Support Center (MUSC) at DLR. Vacuum, UV radiation, and temperature fluctuations are simulated according to the telemetry data measured during flight. The spectroscopic measurements of these two carriers have been performed together with the returned flight samples. We report on the scientific experiment, the details of the ground control analysis, and preliminary flight sample results. We discuss how extended space exposure experiments allow to enhance our knowledge on the evolution of organic compounds in space.
Simons, Jack
Syllabus Chemistry 1225 Summer 2013 Instructor: David Thomas: You must obtain a copy of the Chemistry 1225 lab manual Experiments in General Chemistry Featuring MeasureNet® from the University Bookstore, 2nd
Organization and Analysis of Data from the Qweak Experiment
NASA Astrophysics Data System (ADS)
Cargill, Dan; Spayde, Damon
The Qweak experiment, which was conducted at the Thomas Jefferson National Accelerator Facility in a collaboration consisting of over twenty institutions, measured the small parity violating asymmetry occurring in elastic e-p scattering at low four-momentum transfer. This asymmetry will be used to calculate a precise value for the proton's weak charge. The Standard Model firmly predicts this weak charge based on the running of the weak mixing angle from the Z0 pole (where it is anchored by precise measurements) down to low energies. Through testing this prediction the Qweak experiment hopes to either constrain or reveal possible new physics beyond the Standard Model. Because of the small size of the predicted asymmetry and the precise nature of the measurement, over 2000 hours of data were taken. In order to help organize and store this data, a database has been implemented containing averages over sets of this data. It must be organized in such a way as to allow the quick and easy retrieval of data by collaborators with minimal knowledge of the database language. Tools for aggregating and expanding parts of this database as well as data analysis will be discussed.
TCD-IISc Symposium "Chemistry & Chemical Biology"
O'Mahony, Donal E.
TCD-IISc Symposium "Chemistry & Chemical Biology" Trinity College Clive Williams, Dean of Chemistry. Research areas include supramolecular organic and inorganic chemistry and medicinal chemistry, robotics, structure-function relationships. Sylvia Draper, Professor in Chemistry. Her research spans
"OrganicPad": An Interactive Freehand Drawing Application for Drawing Lewis Structures and the Development of Skills in Organic Chemistry
ERIC Educational Resources Information Center
Cooper, Melanie M.; Grove, Nathaniel P.; Pargas, Roy; Bryfczynski, Sam P.; Gatlin, Todd
Lewis structures are important for learning chemistry as they serve as an essential link between the structure of chemical compounds and their function. Unfortunately, the creation of valid Lewis structures remains an elusive goal for many students. In recent years, several web-based programs have been created that allow students to receive…
Photo-oxidation of pinonaldehyde at low NOx: from chemistry to organic aerosol formation
NASA Astrophysics Data System (ADS)
Chacon-Madrid, H. J.; Henry, K. M.; Donahue, N. M.
Pinonaldehyde oxidation by OH radicals under low-NOx conditions produces significant secondary organic aerosol (SOA) mass yields. Under concurrent UV illumination, mass yields are lower than high-NOx yields published earlier by our group. However, when OH radicals are produced via dark ozonolysis the SOA mass yields are comparable at high and low NOx. Because pinonaldehyde is a major first-generation gas-phase product of ?-pinene oxidation by either ozone or OH radicals, its potential to form SOA serves as a molecular counterpoint to bulk SOA aging experiments involving SOA formed from ?-pinene. Both the general tendency for aging reactions to produce more SOA and the sensitivity of the low-NOx products to UV photolysis observed in the bulk clearly occur for this single species as well. Photochemical oxidation of pinonaldehye and analogous first-generation terpene oxidation products are potentially a significant source of additional SOA in biogenically influenced air masses.
Photo-oxidation of pinonaldehyde at low NOx: from chemistry to organic aerosol formation
NASA Astrophysics Data System (ADS)
Chacon-Madrid, H. J.; Henry, K. M.; Donahue, N. M.
Pinonaldehyde oxidation by OH radicals under low-NOx conditions produces significant secondary organic aerosol (SOA) mass yields. Under concurrent UV illumination, mass yields are lower than high-NOx yields published earlier by our group. However, when OH radicals are produced via dark ozonolysis the SOA mass yields are comparable at high and low NOx. Because pinonaldehyde is a major first-generation gas-phase product of ?-pinene oxidation by either ozone or OH radicals, its potential to form SOA serves as a molecular counterpoint to bulk SOA aging experiments involving SOA formed from ?-pinene. Both the general tendency for aging reactions to produce more SOA and the sensitivity of the low-NOx products to UV photolysis observed in the bulk clearly occur for this single species as well. Photochemical oxidation of pinonaldehye and analogous first-generation terpene oxidation products are potentially a significant source of additional SOA in biogenically influenced air masses.
Phytoplankton responses and associated carbon cycling during shipboard carbonate chemistry manipulation experiments conducted around Northwest European shelf seas
NASA Astrophysics Data System (ADS)
Richier, S.; Achterberg, E. P.; Dumousseaud, C.; Poulton, A. J.; Suggett, D. J.; Tyrrell, T.; Zubkov, M. V.; Moore, C. M.
The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which may reflect community/environment-specific responses or inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series (n = 8) of short-term (2-4 days) multi-level (?4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically separated experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterised by a suppression of net growth for small-sized cells (<10 ?m), were observed in the majority of the experiments, irrespective of natural or manipulated nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasise how biogeochemical feedbacks may be altered in the future ocean.
Heavy-ion-induced production and preseparation of short-livedisotopes for chemistry experiments
Dullmann, Christoph E.; Folden III, Charles M.; Gregorich, Kenneth E.; Hoffman, Darleane C.; Leitner, Daniela; Pang, Gregory K.; Sudowe, Ralf; Zielinski, Peter M.; Nitsche, Heino
Physical separation of short-lived isotopes produced inheavy-ion-induced fusion reactions is a powerful and well know method andoften applied in investigations of the heaviest elements, called thetransactinides (Z>=104). By extracting these isotopes from a recoilseparator, they can be made available for transport to setups locatedoutside the heavily shielded irradiation position such as chemistrysetups. This physical preseparation technique overcomes many limitationscurrently faced in the chemical investigation of transactinides. Here wedescribe the basic principle using relatively short-lived isotopes of thelighter group 4 elements zirconium (Zr) and hafnium (Hf) that are used asanalogs of the lightest transactinide element, rutherfordium (Rf, element104). The Zr and Hf isotopes were produced at the LBNL 88-Inch Cyclotronusing a cocktail of 18O and 50Ti beams and the appropriate targets.Subsequently, the isotopes were physically separated in the BerkeleyGas-filled Separator (BGS) and guided to a Recoil Transfer Chamber (RTC)to transfer them to chemistry setups. The magnetic rigidities of thereaction products in low-pressure helium gas were measured and theiridentities determined with gamma-pectroscopy. Using preseparated isotopeshas the advantages of low background and beam plasma free environment forchemistry experiments. The new possibilities that open up for chemicalinvestigations of transactinide elements are descr ibed. The method canreadily be applied to homologous elements within other groups in theperiodic table.
Crystallizing Classroom Chemists: From Isolated Disorder to Organized Interaction in the Teaching of Chemistry. A History of the Effort To Create a National Chemical Education Organization
NASA Astrophysics Data System (ADS)
Bohning, James J.
Chemistry was an integral part of the culture of the earliest settlements in America, but for almost two centuries it languished as a nascent profession, plagued in part by a lack of suitable textbooks and a "dearth of competent teachers". A few individuals, such as Benjamin Silliman and Amos Eaton, acted as seed crystals in attracting and preparing some chemistry teachers, yet as late as the beginning of World War I, "the average isolated teacher had to work out his own salvation as best he could with the aid of an occasional book agent". Small regional organizations of teachers did exist at this time, but achieved little in connecting teachers on a national level. It was out of this amorphous mixture that the American Chemical Society's Division of Chemical Education (DIVCHED) solidified, uniting at last a dedicated group of teachers with common problems and a passionate dedication to their discipline and their students.
Bridging the Cognitive-Affective Gaps: Teaching Chemistry while Advancing Affective Objectives. The Singapore Curricular Experience
ERIC Educational Resources Information Center
Tan, Kok Siang; Goh, Ngoh Khang; Chia, Lian Sai
Chemistry teachers face constraints when trying to integrate cognitive and affective objectives, and hence thoughtful lesson planning is required to achieve the goal. Chemistry teachers can educate students to be knowledgeable about chemical concepts, processes and the benefits of responsible practice by the chemical industry, while being aware,…
Updated May 2012 Chemistry Degree Requirements
Cina, Jeff
(Majors) 399 342 343 Organic Chemistry Lab 337 338 339 Physical Chemistry 411 412 413 Physical Chemistry courses at the 400-level in Chemistry, Geology and Physics Option 2) One approved course at the 400-level Computational Chemistry CH 410 Physical Organic Chemistry I CH 410 Inorganic Chemistry CH 431 Bioinorganic
Updated September 2012 Chemistry Degree Requirements
Cina, Jeff
Chemistry (Majors) 341 342 343 Organic Chemistry Lab 337 348* 349* Physical Chemistry 411 412 413 Physical approved courses at the 400-level in Chemistry, Geology and Physics Option 2) One approved course Winter Spring Computational Chemistry CH 410 Physical Organic Chemistry I CH 410 Inorganic Chemistry CH
Incorporation of the CrossFire Beilstein Database into the Organic Chemistry Curriculum at the Royal Danish School of Pharmacy
NASA Astrophysics Data System (ADS)
Brřgger Christensen, S.; Franzyk, Henrik; Frřlund, Bente; Jaroszewski, Jerzy W.; Stćrk, Dan; Vedsř, Per
The CrossFire Beilstein database has been incorporated into the organic chemistry curriculum at the Royal Danish School of Pharmacy as a powerful pedagogic tool. During a laboratory course in organic synthesis the database enables the students to get comprehensive overviews of known synthetic methods for a given compound. During a laboratory course in identification and as a part of an applied course in organic spectroscopy the students use the database for obtaining lists of all recorded isomeric compounds, facilitating an exhaustive identification. The main entrances for identification purposes are molecular formulas deduced either from titrations or from mass spectra combined with partial structures identified by chemical tests, or by interpretation of spectra. Thus, identifications made using the CrossFire Beilstein database will exclude some possibilities and point to correct structures from a selection of existing compounds. This appears to help the learning process considerably.
Doyle, Robert
326: Organic Chemistry Laboratory II (2) CHE 474: Structural and Physical Biochemistry I (3) 2: Intermediate Organic Chemistry (3) CHE 436: Advanced Physical Chemistry (3) CHE 467: Introduction to PhysicalB.A. DEGREE REQUIREMENTS FOR CHEMISTRY (BIOLOGICAL CHEMISTRY TRACK) Requirements include 21 credits
Doyle, Robert
) CHE 346: Physical Chemistry Lecture I (3) CHE 347: Physical Analytical Chemistry Laboratory (2) CHE 356: Physical Chemistry Lecture II (3) CHE 357: Physical Chemistry Laboratory (2) AND CHE 335 (1) CHE 427: Intermediate Organic Chemistry (3) CHE 436: Advanced Physical Chemistry (3) CHE 467
Modeling Atmospheric Secondary Organic Aerosol Dynamics through Chemistry, Emissions, and Partition Theory
NASA Astrophysics Data System (ADS)
Chang, Wayne Li-wen
The detrimental impact on both human health and global climate of atmospheric particular matter (PM) is now well-established. Among the various classifications of PM, a significant portion is comprised of secondary organic aerosol (SOA). Despite its importance, there are still much uncertainty regarding the formation and evolution of SOA in the atmosphere, beginning with the oxidation of organic gases that leads to semi-volatile and low volatility products. The need to further improve the current knowledge SOA is made apparent by the observed large discrepancy between model predictions and field measurements of SOA. Proposed explanations behind the orders of magnitude underprediction of ambient SOA levels by state-of-the-art airshed models include: missing particle-forming oxidized organic products, unidentified SOA precursor emissions, and issues related to the fundamentals of current SOA partition theory, all of which are considered in this study to develop corresponding improvements to the latest airshed models. The model used in this study is the UCI-CIT airshed model, and the improvement scenario tests are set in the urban region of South Coast Air Basin of California. Recent chamber results have shown that the original implementation of alkane-derived SOA provided an underestimate for what was likely to be occurring in urban atmospheres. Thus, the original chemical mechanism is revised to include higher generation products of medium- and long-chain alkanes that can contribute to SOA in this study. Primary organic aerosol (POA) has been identified to be able to evaporate with dilution; therefore, test cases are developed that treat fractions of POA as semi-volatile, a source of SOA, rather than nonvolatile. While current atmospheric models assume that SOA are liquids into which semi-VOCs undergo equilibrium partitioning and grow the particles, recent laboratory and field experiments have shown otherwise. Hence, a new kinetics-driven partition theory is developed and analyzed against the original formulations. The results from the expanded chemical mechanism to include higher-generation products of alkane in the atmosphere shows that only the tetrahydrofurans will contribute to SOA and those contributions are only a small fraction compared to other SOA sources in the model, contrary to the prediction made based on chamber experiments and box models. In the tests for redistribution of POA as gas-phase parent VOCs sources, POA decreased with no commensurate increase in SOA. This is essentially due to the fact that the amount of mass that the POA can contribute is a small fraction of that already in the gas-phase parent VOC pool. Finally, using the newly developed kinetically determined SOA growth mechanism, to achieve the same level of predicted SOA levels as the original equilibrium approach requires 40--50% of SOA parent species to be allocated to the particle phase. The new formulation of SOA partition behavior based on kinetics will require the measurement of new input data and the corresponding parameterization for models in the future. The implication of this new approach should demand wider attention from the community.
Computational and Experimental Assessment of Benzene Cation Chemistry for the Measurement of Marine Derived Biogenic Volatile Organic Compounds with Chemical Ionization Mass Spectrometry
NASA Astrophysics Data System (ADS)
Zoerb, M.; Kim, M.; Zimmermann, K.; Bertram, T. H.
Chemical ionization mass spectrometry (CIMS) is a highly selective and sensitive technique for the measurement of trace gases in the atmosphere. However, competing side reactions and dependence on relative humidity (RH) can make the transition from the laboratory to the field challenging. Effective implementation of chemical ionization requires a thorough knowledge of the elementary steps leading to ionization of the analyte. We have recently investigated benzene cations for the detection of marine derived biogenic volatile organic compounds (BVOCs), such isoprene and terpene compounds, from algal bloom events. Our experimental results indicate that benzene ion chemistry is an attractive candidate for field measurements, and the RH dependence is weak. To further understand the advantages and limitations of this approach, we have also used electronic structure theory calculations to compliment the experimental work. These theoretical methods can provide valuable insight into the physical chemistry of ion molecule reactions including thermodynamical information, the stability of ions to fragmentation, and potential sources of interference such as dehydration to form isobaric ions. The combined experimental and computational approach also allows validation of the theoretical methods and will provide useful information towards gaining predictive power for the selection of appropriate reagent ions for future experiments.
Extraction and Quantitation of FD&C Red Dye #40 from Beverages Containing Cranberry Juice: A College-Level Analytical Chemistry Experiment
ERIC Educational Resources Information Center
Rossi, Henry F., III; Rizzo, Jacqueline; Zimmerman, Devon C.; Usher, Karyn M.
A chemical separation experiment can be an interesting addition to an introductory analytical chemistry laboratory course. We have developed an experiment to extract FD&C Red Dye #40 from beverages containing cranberry juice. After extraction, the dye is quantified using colorimetry. The experiment gives students hands-on experience in using solid…
Carbon Dioxide (CO2) Retrievals from Atmospheric Chemistry Experiment (ACE) Solar Occultation Measurements
NASA Technical Reports Server (NTRS)
Rinsland, Curtis P.; Chiou, Linda; Boone, Chris; Bernath, Peter
The Atmospheric Chemistry Experiment ACE satellite (SCISAT-1) was launched into an inclined orbit on 12 August 2003 and is now recording high signal-to-noise 0.02 per centimeter resolution solar absorption spectra covering 750-4400 per centimeter (2.3-13 micrometers). A procedure has been developed for retrieving average dry air CO2 mole fractions (X(sub CO2)) in the altitude range 7-10 kilometers from the SCISAT-1 spectra. Using the N2 continuum absorption in a window region near 2500 per centimeter, altitude shifts are applied to the tangent heights retrieved in version 2.2 SCISAT-1 processing, while cloudy or aerosol-impacted measurements are eliminated. Monthly-mean XCO2 covering 60 S to 60 N latitude for February 2004 to March 2008 has been analyzed with consistent trends inferred in both hemispheres. The ACE XCO2 time series have been compared with previously-reported surface network measurements, predictions based on upper tropospheric aircraft measurements, and space-based measurements. The retrieved X(sub CO2) from the ACE-FTS spectra are higher on average by a factor of 1.07 plus or minus 0.025 in the northern hemisphere and by a factor of 1.09 plus or minus 0.019 on average in the southern hemisphere compared to surface station measurements covering the same time span. The ACE derived trend is approximately 0.2% per year higher than measured at surface stations during the same observation period.
Projectile compositions and modal frequencies on the chemistry of micrometeoroids LDEF experiment
NASA Astrophysics Data System (ADS)
Bernhard, Ronald P.; See, Thomas H.; Hoerz, Friedrich
The Chemistry of Micrometeoroids Experiment (LDEF instrument A0187-1) exposed witness plates of high-purity gold (greater than 99.99 percent Au) and commercial aluminum (greater than 99 percent Al) with the objective of analyzing the residues of cosmic-dust and orbital-debris particles associated with hypervelocity impact craters. The gold substrates were located approximately 8 deg off LDEF's trailing edge (Bay A03), while the aluminum surfaces resided in Bay A11, approximately 52 deg from LDEF's leading edge. SEM-EDX techniques were employed to analyze the residues associated with 199 impacts on the gold and 415 impacts on the aluminum surfaces. The residues that could be analyzed represent natural or man-made materials. The natural particles dominate at all particle sizes less than 5 micron. It is possible to subdivide both particle populations into subclasses. Chondritic compositions dominate the natural impactors (71 percent), followed by monomineralic, mafic-silicate compositions (26 percent), and by Fe-Ni rich sulfides (approximately 3 percent). Approximately 30 percent of all craters on the gold collectors were caused by man-made debris such as aluminum, paint flakes, and other disintegrated, structural and electronic components. Equations-of-state and associated calculations of shock stresses for typical LDEF impacts into the gold and aluminum substrates suggest that substantial vaporization may have occurred during many of the impacts and is the reason why approximately 50 percent of all craters did not contain sufficient residue to permit analysis by the SEM-EDX technique. After converting the crater diameters into projectile sizes using encounter speeds typical for the trailing-edge and forward-facing (Row 11) directions, and accounting for normalized exposure conditions of the CME collectors, we derived the absolute and relative fluxes of specific projectile classes. The natural impactors encounter all LDEF pointing directions with comparable, modal frequencies suggesting compositional (and dynamic) homogeneity of the interplanetary-dust environment in near-Earth orbit.
Evaluation of the MOCAGE chemistry transport model during the ICARTT/ITOP experiment
NASA Astrophysics Data System (ADS)
Bousserez, N.; Attié, J. L.; Peuch, V. H.; Michou, M.; Pfister, G.; Edwards, D.; Emmons, L.; Mari, C.; Barret, B.; Arnold, S. R.; Heckel, A.; Richter, A.; Schlager, H.; Lewis, A.; Avery, M.; Sachse, G.; Browell, E. V.; Hair, J. W.
Intercontinental Transport of Ozone and Precursors (ITOP), part of International Consortium for Atmospheric Research on Transport and Transformation (ICARTT), was a large experimental campaign designed to improve our understanding of the chemical transformations within plumes during long-range transport (LRT) of pollution from North America to Europe. This campaign took place in July and August 2004, when a strong fire season occurred in North America. Burning by-products were transported over large distances, sometimes reaching Europe. A chemical transport model, Modélisation de la Chimie Atmosphérique Grande Echelle (MOCAGE), with a high grid resolution (0.5° × 0.5°) over the North Atlantic area and a daily inventory of biomass burning emissions over the United States, has been used to simulate the period. By comparing our results with available aircraft in situ measurements and satellite data (MOPITT CO and SCIAMACHY NO2), we show that MOCAGE is capable of representing the main characteristics of the tropospheric ozone-NOx-hydrocarbon chemistry during the ITOP experiment. In particular, high resolution allows the accurate representation of the pathway of exported pollution over the Atlantic, where plumes were transported preferentially at 6 km altitude. The model overestimates OH mixing ratios up to a factor of 2 in the lower troposphere, which results in a global overestimation of hydrocarbons oxidation by-products (PAN and ketones) and an excess of O3 (30-50 ppbv) in the planetary boundary layer (PBL) over the continental United States. Sensitivity study revealed that lightning NO emissions contributed significantly to the NOx budget in the upper troposphere of northeast America during the summer 2004.
Projectile compositions and modal frequencies on the chemistry of micrometeoroids LDEF experiment
NASA Technical Reports Server (NTRS)
Bernhard, Ronald P.; See, Thomas H.; Hoerz, Friedrich
The Chemistry of Micrometeoroids Experiment (LDEF instrument A0187-1) exposed witness plates of high-purity gold (greater than 99.99 percent Au) and commercial aluminum (greater than 99 percent Al) with the objective of analyzing the residues of cosmic-dust and orbital-debris particles associated with hypervelocity impact craters. The gold substrates were located approximately 8 deg off LDEF's trailing edge (Bay A03), while the aluminum surfaces resided in Bay A11, approximately 52 deg from LDEF's leading edge. SEM-EDX techniques were employed to analyze the residues associated with 199 impacts on the gold and 415 impacts on the aluminum surfaces. The residues that could be analyzed represent natural or man-made materials. The natural particles dominate at all particle sizes less than 5 micron. It is possible to subdivide both particle populations into subclasses. Chondritic compositions dominate the natural impactors (71 percent), followed by monomineralic, mafic-silicate compositions (26 percent), and by Fe-Ni rich sulfides (approximately 3 percent). Approximately 30 percent of all craters on the gold collectors were caused by man-made debris such as aluminum, paint flakes, and other disintegrated, structural and electronic components. Equations-of-state and associated calculations of shock stresses for typical LDEF impacts into the gold and aluminum substrates suggest that substantial vaporization may have occurred during many of the impacts and is the reason why approximately 50 percent of all craters did not contain sufficient residue to permit analysis by the SEM-EDX technique. After converting the crater diameters into projectile sizes using encounter speeds typical for the trailing-edge and forward-facing (Row 11) directions, and accounting for normalized exposure conditions of the CME collectors, we derived the absolute and relative fluxes of specific projectile classes. The natural impactors encounter all LDEF pointing directions with comparable, modal frequencies suggesting compositional (and dynamic) homogeneity of the interplanetary-dust environment in near-Earth orbit.
The Mars Environmental Compatibility Assessment (MECA) Wet Chemistry Experiment on the Mars 2001 Lander
NASA Astrophysics Data System (ADS)
Grannan, S. M.; Frant, M.; Hecht, M. H.; Kounaves, S. P.; Manatt, K.; Meloy, T. P.; Pike, W. T.; Schubert, W.; West, S.; Wen, X.
The Mars Environmental Compatibility Assessment (MECA) is an instrument suite that will fly on the Mars Surveyor 2001 Lander Spacecraft. MECA is sponsored by the Human Exploration and Development of Space (HEDS) program and will evaluate potential hazards that the dust and soil of Mars might present to astronauts and their equipment on a future human mission to Mars. Four elements constitute the integrated MECA payload: a microscopy station, patch plates, an electrometer, and the wet chemistry laboratory (WCL). The WCL consists of four identical cells, each of which will evaluate a sample of Martian soil in water to determine conductivity, pH, redox potential, dissolved C02 and 02 levels, and concentrations of many soluble ions including sodium, potassium, magnesium, calcium and the halides. In addition, cyclic voltammetry will be used to evaluate reversible and irreversible oxidants present in the water/soil solution. Anodic stripping voltammetry will be used to measure concentrations of trace metals including lead, copper, and cadmium at ppb levels. Voltammetry is a general electrochemical technique that involves controlling the potential of an electrode while simultaneously measuring the current flowing at that electrode. The WCL experiments will provide information on the corrosivity and reactivity of the Martian soil, as well as on soluble components of the soil which might be toxic to human explorers. They will also guide HEDS scientists in the development of high fidelity Martian soil simulants. In the process of acquiring information relevant to HEDS, the WCL will assess the chemical composition and properties of the salts present in the Martian soil.
A Continuum of Learning: From Rote Memorization to Meaningful Learning in Organic Chemistry
ERIC Educational Resources Information Center
Grove, Nathaniel P.; Bretz, Stacey Lowery
The Assimilation Theory of Ausubel and Novak has typically been used in the research literature to describe two extremes to learning chemistry: meaningful learning "versus" rote memorization. It is unlikely, however, that such discrete categories of learning exist. Rote and meaningful learning, rather, are endpoints along a continuum of learning.…
SELF-ASSEMBLING AMPHIPHILIC MOLECULES: A POSSIBLE LINKAGE BETWEEN INTERSTELLAR CHEMISTRY by ionizing radiation [2,3]. Here we discuss the production of amphiphilic materials that can spon- taneously,5,6]. The presence of amphiphilic molecules is further con- firmed by surface tension measurements. These spe- cies
Projects that Assist with Content in a Traditional Organic Chemistry Course
ERIC Educational Resources Information Center
Esteb, John J.; Magers, John R.; McNulty, LuAnne; Wilson, Anne M.
Two projects, the reaction notebook and the end-of-semester synthesis activity are described which could help students to adopt a discovery-based learning and engage students in practical applications of chemistry. Students have provided positive feedback on this classroom assignment and have felt that it has helped them crystallize their thought…
Inverted Teaching: Applying a New Pedagogy to a University Organic Chemistry Class
ERIC Educational Resources Information Center
Christiansen, Michael A.
Inverted teaching, not to be confused with hybrid learning, is a relatively new pedagogy in which lecture is shifted outside of class and traditional homework is done in class. Though some inverted teaching (IT) designs have been published in different fields, peer-reviewed reports in university chemistry remain quite rare. To that end, herein is…
The development of the Space Environment Viability of Organics (SEVO) experiment aboard the Organism\\/Organic Exposure to Orbital Stresses (O\\/OREOS) satellite
Nathan E. Bramall; Richard Quinn; Andrew Mattioda; Kathryn Bryson; Julie D. Chittenden; Amanda Cook; Cindy Taylor; Giovanni Minelli; Pascale Ehrenfreund; Antonio J. Ricco; David Squires; Orlando Santos; Charles Friedericks; David Landis; Nykola C. Jones; Farid Salama; Louis J. Allamandola; Sřren V. Hoffmann
The Space Environment Viability of Organics (SEVO) experiment is one of two scientific payloads aboard the triple-cube satellite Organism\\/ORganic Exposure to Orbital Stresses (O\\/OREOS). O\\/OREOS is the first technology demonstration mission of the NASA Astrobiology Small Payloads Program. The 1-kg, 1000-cm3 SEVO cube is investigating the chemical evolution of organic materials in interstellar space and planetary environments by exposing organic
Determining the Quantum Efficiency for Activation of an Organometallic Photoinitiator for Cationic Polymerization: An Experiment for the Physical or Inorganic Chemistry Laboratory
ERIC Educational Resources Information Center
Hayes, David M.; Mahar, Maura; Schnabel, R. Chris; Shah, Paras; Lees, Alistair J.; Jakubek, Vladimir
We present a new laboratory experiment on the photochemistry of organometallic [eta][superscript 5],[eta][superscript 6]-mixed-sandwich compounds, which is suitable for both the physical chemistry and inorganic chemistry laboratory. Specifically, students use 1,10-phenanthroline to trap the intermediate formed when…
The ORGANIC Experiment on EXPOSE-R on the ISS: A Space Exposure Experiment
NASA Astrophysics Data System (ADS)
Bryson, Kathryn; Peeters, Z.; Salama, F.; Foing, B.; Ehrenfreund, P.; Ricco, A.; Jessberger, E. K.; Bischoff, A.; Breitfellner, M.; Schmidt, W.; Robert, F.
Aromatic networks are among the most abundant organic material in space. PAHs and fullerenes have been identified in meteorites and are thought to be among the carriers for numerous astronomical absorption and emission features. Thin films of selected PAHs and fullerenes have been subjected to the low Earth orbit environment as part of the ORGANIC experiment on the multi-user facility EXPOSE-R onboard the ISS. The ORGANIC experiment monitored the chemical evolution, survival, destruction, and chemical modification of the samples. EXPOSE-R was mounted on the outside of the ISS from March 10, 2009 to January 21, 2011. The samples were returned to Earth and inspected in spring 2011. The 682-day period outside the ISS provided continuous exposure to the cosmic-, solar-, and trapped-particle radiation background and >2500 h of unshadowed solar illumination. All trays carry both solar-irradiation-exposed and dark samples shielded from the UV photons, enabling discrimination between the effects of exposure to solar photons and cosmic rays. The samples were analyzed before exposure to the space environment with UV-VIS spectroscopy. Ground truth monitoring of additional sample carriers was performed through UV-VIS spectroscopy at regular intervals at NASA Ames Research Center. During the exposure on the ISS, 2 control sample carriers were exposed with a slight time shift in a planetary simulation chamber at the Microgravity User Support Center at DLR. Vacuum, UV radiation, and temperature fluctuations are simulated according to the telemetry data measured during flight. The spectroscopic measurements of these two carriers have been performed together with the returned flight samples. We report on the scientific experiment, the details of the ground control analysis, and preliminary flight sample results.
Using a Premade Grignard Reagent to Synthesize Tertiary Alcohols in a Convenient Investigative Organic Laboratory Experiment
ERIC Educational Resources Information Center
Berg, Michael A. G.; Pointer, Roy D.
A commercially available Grignard reagent (3.0 M solution of phenyl magnesium bromide in ether) was used in a convenient Grignard synthesis in a second-year organic chemistry laboratory without any of the typical failures associated with the Grignard reaction. The reaction setup used oven-dried glassware and no extraordinary measures were taken to…
Oil Formation: An "Unexpected" Difficulty in an Elementary Organic Laboratory Experiment
ERIC Educational Resources Information Center
Lewis, Dennis A.
Describes an undergraduate organic laboratory experiment involving the separation of an unknown solid organic acid and an unknown solid organic base. The experiment is designed to present the student with an unexpected difficulty, namely, the formation of a separable viscous liquid, to see how the student handles this difficulty. (MLH)
Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol
Massachusetts Institute of Technology; Kroll, Jesse H.; Donahue, Neil M.; Jimenez, Jose L.; Kessler, Sean H.; Canagaratna, Manjula R.; Wilson, Kevin R.; Altieri, Katye E.; Mazzoleni, Lynn R.; Wozniak, Andrew S.; Bluhm, Hendrik; Mysak, Erin R.; Smith, Jared D.; Kolb, Charles E.; Worsnop, Douglas R.
A detailed understanding of the sources, transformations, and fates of organic species in the environment is crucial because of the central roles that organics play in human health, biogeochemical cycles, and Earth's climate. However, such an understanding is hindered by the immense chemical complexity of environmental mixtures of organics; for example, atmospheric organic aerosol consists of at least thousands of individual compounds, all of which likely evolve chemically over their atmospheric lifetimes. Here we demonstrate the utility of describing organic aerosol (and other complex organic mixtures) in terms of average carbon oxidation state (OSC), a quantity that always increases with oxidation, and is readily measured using state-of-the-art analytical techniques. Field and laboratory measurements of OSC , using several such techniques, constrain the chemical properties of the organics and demonstrate that the formation and evolution of organic aerosol involves simultaneous changes to both carbon oxidation state and carbon number (nC).
Effects of activated carbon surface chemistry and pore structure on the adsorption of trace organic contaminants from aqueous solution
NASA Astrophysics Data System (ADS)
Li, Lei
The objectives were (1) to identify activated pore structure and surface chemistry characteristics that assure the effective removal of trace organic contaminants from aqueous-solution, and (2) to develop a procedure to predict the adsorption capacity of activated carbons from fundamental adsorbent and adsorbate properties. A matrix of activated carbon fibers (ACFs) (with three activation levels and four surface chemistry levels) and three commercially available granular activated carbons (GACs) served as the adsorbents. BET surface area, pore size distribution, elemental composition, point of zero charge and infrared spectroscopy data were obtained to characterize the adsorbents. The adsorption of relative hydrophilic methyl tertiary-butyl ether (MTBE) and relative hydrophobic trichloroethene (TCE) were conducted in both ultrapure water and Sacramento-San Joaquin Delta water. The results showed that an effective adsorbent for the removal of micropollutants from water requires (1) a large volume of micropores with widths that are about 1.5 times larger than the kinetic diameter of the target adsorbate, (2) a micropore size distribution that extends to widths that are approximately twice the kinetic diameter of the target adsorbate to prevent pore blockage by NOM, and (3) a hydrophobic pore surface chemistry with the sum of oxygen and nitrogen contents less than 2 to 3 mmol/g. A procedure based on the Polanyi Potential Theory (PPT) was developed to predict the adsorption capacities of activated carbons from fundamental adsorbent and adsorbate properties. A correlation between the coalescing factor for water adsorption and adsorbent oxygen content was developed. Based on this correlation, the PPT yielded reasonable estimates of aqueous phase adsorption capacities for both relatively polar and non-polar adsorbates on both relatively hydrophobic and hydrophilic activated carbons. With the developed procedure, the adsorption capacities of organic compounds that are partially miscible in water can be predicted from (1) N2 and CO2 adsorption isotherms of a given adsorbent, (2) the adsorbent oxygen content, and (3) the molar volume and parachor of the target adsorbate.
Differences in Developmental Experiences for Commonly Used Categories of Organized Youth Activities
ERIC Educational Resources Information Center
Hansen, David M.; Skorupski, William P.; Arrington, Tiffany L.
The coherence of adolescents' self-reported learning experiences between subgroups of organized youth activities within five commonly used categories was evaluated. Data for the present study come from a representative sample of eleventh grade adolescents' reports on learning experiences in an organized youth activity using the Youth Experience…
Gene set analyses for interpreting microarray experiments on prokaryotic organisms.
Tintle, Nathan; Best, Aaron; Dejongh, Matthew; VanBruggen, Dirk; Heffron, Fred; Porwollik, Steffen; Taylor, Ronald C.
Background: Recent advances in microarray technology have brought with them the need for enhanced methods of biologically interpreting gene expression data. Recently, methods like Gene Set Enrichment Analysis (GSEA) and variants of Fisher's exact test have been proposed which utilize a priori biological information. Typically, these methods are demonstrated with a priori biological information from the Gene Ontology. Results: Alternative gene set definitions are presented based on gene sets inferred from the SEED: open-source software environment for comparative genome annotation and analysis of microbial organisms. Many of these gene sets are then shown to provide consistent expression across a series of experiments involving Salmonella Typhimurium. Implementation of the gene sets in an analysis of microarray data is then presented for the Salmonella Typhimurium data. Conclusions: SEED inferred gene sets can be naturally defined based on subsystems in the SEED. The consistent expression values of these SEED inferred gene sets suggest their utility for statistical analyses of gene expression data based on a priori biological information
Chemistry of small organic molecules on snow grains: the applicability of artificial snow for environmental studies.
Kurková, Romana; Ray, Debajyoti; Nachtigallová, Dana; Klán, Petr
The utilization of artificial snow for environmentally relevant (photo)chemical studies was systematically investigated. Contaminated snow samples were prepared by various methods: by shock freezing of the aqueous solutions sprayed into liquid nitrogen or inside a large walk-in cold chamber at -35 °C, or by adsorption of gaseous contaminants on the surface of artificially prepared pure or natural urban snow. The specific surface area of artificial snow grains produced in liquid nitrogen was determined using valerophenone photochemistry (400-440 cm(2) g(-1)) to estimate the surface coverage by small hydrophobic organic contaminants. The dynamics of recombination/dissociation (cage effect) of benzyl radical pairs, photochemically produced from 4-methyldibenzyl ketone on the snow surface, was investigated. The initial ketone loading, c = 10(-6)-10(-8) mol kg(-1), only about 1-2 orders of magnitude higher than the contaminant concentrations commonly found in nature, was already well below monolayer coverage. We found that the efficiency of out-of-cage reactions decreased at much higher temperatures than those previously determined for frozen solutions; however, the cage effect was essentially the same no matter what technique of snow production or ketone deposition/uptake was used, including the experiments with collected natural snow. The experimental observation that the contaminant molecules are initially self-associated even at the lowest concentrations was supported by DFT calculations. We conclude that, contrary to frozen aqueous solutions, in which the impurities reside in a 3D cage (micropocket), contaminant molecules located on the artificial snow grain surface at low concentrations can be visualized in terms of a 2D cage. Artificial snow thus represents a readily available study matrix that can be used to emulate the natural chemical processes of trace contaminants occurring in natural snow. PMID:21366308
NSDL National Science Digital Library
Developed by the University of Leeds, the Delights of Chemistry promotes the art of chemistry demonstrations. Users can find illustrations and explanations of forty chemistry experiments. Many animations of demonstrations including the magnesium lamp, thermite reaction, and the volcano reaction are available. The website is full of pictures of chemistry equipment and scientists at work. Through this site, students and educators are able to explore fun chemistry experiments without having to worry about the many hazards associated with working with chemicals.

subset: commoncrawl