explain crystiallization and how crystal of copper sulphate prepared - science - physical and chemical changes
explain crystiallization and how crystal of copper sulphate
prepared?
hey there! as answered previously:-
crystallization is the process of slow precipitation of solid
crystals of a substance from a concentrated homogeneous solution it
is basically a separation method in which a substance is
transferred from the liquid (i e solution) phase to the solid state
the substance is thus obtained in pure crystalline form and has no
impurity it is used by chemists for the purification of solid
substances
following is an example of using crystallization to obtain pure
copper sulphate from an impure sample
1) take a small amount (5 g) of an impure sample of copper
sulphate in a china dish
2) dissolve the sample in 10 ml of water (we basically have to
use minimum amount of water in order to prepare a saturated
solution)
3) then, filter it to remove impurities
4) evaporate the filtrate on a water bath till small crystals
are formed indicating that a concentrated solution has been
obtained
5) after this, cover the solution with a filter paper and leave
it undisturbed at room temperature for the rest of the day
![](https://img-nm%20mnimgs%20com/img/study_content/lp/1/9/8/114/318/760/662/5-6-08_sonali_9_chemistry_9%202%202%202%201_gsx_sg_ss_html_3c9d32fa%20png)
it will be observed that crystals of pure copper sulphate are
obtained and the impurities are left behind in the solution
sr2+ → strontium cl- → chloride[readmore]therefore the chemical name will appear as strontium chloride we are going to do the following steps:step 1: determine the classification of the compoundstep 2: write the formula of the compound[readmore]step 1: determine the classification of the compoundrecall the definition of the following:ionic compound - usually made up of a metal and a non-metalcovalent compound - composed of more than one nonmetal togetheracid - substance whose molecules yield hydrogen ions (h+) when dissolved in waterhydrate - substance that contains water or its constituent elementsfor cobaltic iodidecobaltic – metaliodide – nonmetalmetal + nonmetal = ionicstep 2: write the formula of the compoundthe rules for naming ionic compounds are as follows:1. the metal keeps its name and is named and written first.– for transition metals, we use roman numerals to denote its charge.2. the nonmetal keeps its base name but has its ending changed to –ide.for cobaltic iodidecobaltic  → transition metal → +2 charge → co2+iodide → group 7a → -1 charge → i-criss-cross the charges and make them the subscript of the other ioncobaltic iodide → coi2answer: cobaltic iodide is an ionic compound with a formula of coi2 on sapling its

oxidation:
cu --> cu^2+ + 2e^-

reduction:
o\_2 + 4e^- -->2o^2- (a) the candidate was studying the effect/importance of sunlight on the rate of photosynthesis.explanation: the candidate had covered one part of the leaf to study the rate of photosynthesis in the absence of sunlight. the candidate would compare it with the rate of photosynthesis on the uncovered parts of the leaf and thus, determine the role of sunlight during photosynthesis.(b) yes, the uncovered portion of the leaf of the potted plant is used as the control here.explanation: the control is used to compare the results which will be obtained after the experiment with the covered portion of the leaf to obtain conclusions.(c) plant was kept in the dark before the experiment, to remove the starch present in the leaf, to the storage organs.explanation: destarching is done by placing the plant for 24-48 hours in darkness before starting the experiment. this is done to make sure that all starch has been formed under experimental conditions only.(d) 1) first, the candidate would have dipped the prepared leaf in boiling water to kill the leaf cells.2) then he would have boiled the leaf in methylated spirit to remove the chlorophyll.3) the leaf would have then been placed in hot water to soften it.4) he would have placed it in a dish and poured iodine solution. the presence of starch is confirmed in regions that turn bluish-black in colour.the uncovered portion of the leaf would have turned bluish black and the cover region would have turned brown in colour.explanation: the uncovered portion of the leaf would have turned bluish black as starch would have formed in those regions. sunlight activates the chlorophyll, which in turn catalyzes the photosynthesis reaction. in the covered portion, on which sunlight could not have penetrated, the region turns brown due to the absence of chlorophyll. this implies that photosynthesis would not have taken place on the covered portion of the leaf. hi there!we are asked to determine the process corresponding to the increase in entropy labeled 1 and 2.we can use the heating curve to answer the given questions. recall that entropy is the degree of chaos or disorder of a system. for a given process, entropy (δs) will either increase or decrease. also, phase changes lead to a change in entropy:• we know that the phase at the highest temperature is gas• the plot has 2 process with drastic increase in entropy.• increase in entropy accompanying phase change is from solid → liquid → gas• therefore, the phases in the graph must have been:• phase change from solid to liquid is called fusion or melting• phase change from liquid to gas is called vaporizationprocess 1 represents melting (fusion), and 2 represents vaporization. chocolate syrup is something that is added to desserts to make them taste better. people will pour chocolate syrup to vanilla ice cream or they will stir it into their milk to make chocolate milk. however, it is quite easy to obtain The answer to the question is available in the PDF file https://www.assignmentexpert.com/https://www.assignmentexpert.com/homework-answers/chemistry-answer-84648.pdf The answer to the question is available in the PDF file https://www.assignmentexpert.com/https://www.assignmentexpert.com/homework-answers/chemistry-answer-56578.pdf we’re being asked which of the following conditions occurs when a chemical change happens to a piece of wood let’s first define a physical change and a chemical change.physical change → there is a change in a matter as it goes from one physical state to another.chemical change → atoms rearrange themselves to create a new substance. now, let’s take a look at each condition:[readmore]a. is splitsplitting wood is only reducing its size. physical changeb. is paintedpainting wood is only placing paint on top of it and not really affecting the composition of the wood.  physical changec. decaysdecaying changes the integrity of the wood itself and transforms it into things like soil. chemical changed. is cutcutting wood is only reducing its size. physical changea chemical change occurs when a piece of wood c. decays. The answer to the question is available in the PDF file https://www.assignmentexpert.com/homework-answers/chemistry-answer-49762.pdf