hcl is a polar molecule, how come the intermolecul...
hcl is a polar molecule, how come the intermolecular forces among its molecules consist of london dispersion force besides dipole dipole attraction ?
recall that there are several types of intermolecular forces:1. ion-dipole interaction – occurs between an ion and a polar covalent compound2. hydrogen bonding – occurs in compounds where hydrogen is directly connected to an electronegative element such as n, o, or f3. dipole-dipole interaction – occurs between two polar covalent compounds4. induced-dipole interaction – occurs when a nonpolar compound interacts with a polar compound5. dispersion forces – occurs in all compounds. this is the primary intermolecular force exhibited by nonpolar compounds.[readmore]although hcl is a polar molecule, it still exhibits dispersion forces because it occurs in all compounds
hydrogen gas in its natural state consists of molecules of h2, where two hydrogen atoms are bound together by a 100% covalent bond.

the h2 molecules are attracted to each other by london dispersion forces. london dispersion forces result from the formation of temporary dipoles. (i) adsorption is a surface phenomenon that causes the accumulation of molecules of a substance at the surface of a solid or liquid rather than in the bulk. in adsorption, the substance gets concentrated at the surface only. it does not penetrate through the surface to the bulk of the solid or liquid. for example, when a chalk stick is dipped into an ink solution, only its surface becomes coloured.


on the other hand, the process of absorption is a bulk phenomenon. in absorption, the absorbed substance gets uniformly distributed throughout the bulk of the solid or liquid. for example, when a sponge is dipped in water the whole sponge gets wets.


(ii)according to the schulze-hardy rule, the effectiveness of the salt causing flocculation depends on the charge on the ion of opposite sign to the charge on the sol particles. the greater the magnitude of the opposite charge, the higher the ability of a salt to coagulate the sol.  
thus, trivalent salt alcl3 is more effective in causing the coagulation of a negatively charged sol than divalent salt mgcl2.


(iii)out of sulphur sol and proteins, sulphur sol forms multimolecular colloids. sulphur sol consists of particles containing a thousand or more s8 molecules. on the other hand, proteins form macromolecular colloids. that depends on a lot of things. in particular, you would need to find the electric susceptibility of the paper. the field produced by static charge is inverse-square. the polarization of the paper varies directly with the external field, with a proportionality constant equal to the electric susceptibility. the dipole field created by the polarized paper is inverse-cube. overall, the force between the ruler and the paper will vary with the inverse fifth power of distance. to get any more detailed, you would need to know the geometry of the situation, and the charge distribution. Because only HBr produces a Br-radical (in presence of peroxide), which then reacts with the double bond. It is considered that HF and HCl are too stable to produce free radicals. HI produces I-radicals, but they have not enough activity for starting of radical chain reaction.  
This is also known as “the peroxide effect” or “the Kharasch effect”. chloroplast is a powerhouse for the synthesis of carbohydrates in plants. it is broadly divided into three parts (fig 3) namely:a) membrane: chloroplast is double walled organelle viz. it contains inner and outer membrane.b) stroma corresponds to the cytoplasm of chloroplast. it also serves as site for dark reaction of photosynthesis to take place.c) thylakoids/ granum: thylakoids contains chlorophyll that absorbs light. stacks of thylakoids are known as granum.fig 3 shows different parts of chloroplast yes, the plants have chloroplasts and they have chromoplasts. 

chromoplasts contain pigments, just like chloroplasts, but the pigments are not photosynthetic. their abundant pigments overwhelm the light reflected from the chloroplasts making the leaf another color. chromoplasts are what color flowers, fruit and other plant parts. the function of chromoplasts pigments can be as a signal or protective.

chromoplast content in leaves varies naturally in plants. plants with more chromoplasts can survive regions of marginal nutrient resources because they are better protected from both oxidative and uv stress. the green leaved sugar maple is more sensitive to nutrient stresses associated with low ph soils than the red maple acer rubrum. acidic soils are less fertile. an increase in chromoplast content can mediate the negative effects of nutrient imbalances on maples by relieving uv & oxidative stress. red maples can out compete other maples for nutrient poor acidic soils by having more chromoplasts. 
http://www.ingentaconnect.com/content/bsc/pce/2005/00000028/00000007/art00005 
http://www.rsc.org/delivery/\_articlelinking/displayhtmlarticleforfree.cfm?journalcode=pp&year=2005&manuscriptid=b417802e&iss=4

chromoplasts content in flowers signals to pollinators while in fruit it signals to seed dispersers when the plant is ready for them. chromoplasts are not different organelles they are chloroplasts that continued to mature with regulation to produce more carotenoids or anthocyanins than chlorophylls. 1. according to kinetic theory of ideal gases, molecules of a gas are in incessant random motion, colliding against each other and with the walls of the container. all these collisions are perfectly elastic collision.2. in perfectly elastic collision, total kinetic energy of gas is conserved.3. here, we have a mixture of oxygen and hydrogen gas. thereforek.e of oxygen + k.e of hydrogen=constant4. so, if kinetic energy of oxygen molecules increases, then kinetic energy of hydrogen molecules decreases or vice-versa so that, sum of both kinetic energies remains constant.5. therefore, both option (c) and (d) are correct. answer: the molecular mass of an element is defined as the sum of the masses of the elements present in the molecule. molecular mass is obtained by multiplying the atomic mass of an element with the number of atoms in the molecule and then adding the masses of all the elements in the molecule. o2 is a diatomic molecule. the mass of an oxygen atom = 16 amu. ∴ mass of o2 molecule = 2 × 16 = 32 amu. mass of one molecule of oxygen → 32/ avogadro constant ( 6.023 × 1023) → 5.31 × 10-23g. i. given:valency of carbon is 4valency of chlorine is 1by applying criss-cross method:formula: ccl4thus, the formula for carbon tetrachloride is ccl4.ii. given:valency of element x is 1valency of oxygen is 2by applying criss-cross method:formula: x2o an alloy is combination of a metal and a non metal. so it has partial characteristics of metal and non metal. being analloy the ions it it are randomly arranged. it does not have a specific arrangement of ions. hence the flow of electrons in this is more. the this feature of alloy leads to increase in resistivity due to free crystal lattice. we know that metals have high melting point but an alloy has low melting point beacause the presence of a non metal in it behaves as an impurity and restricts in raising to high melting point. due to high melting point the it takes a lot of current to melt and leads in slow movement of electrons which makes the device less efficient. therefore electronic device requires the metal of low melting point. an alloy plays the best role in the elctronic device like electric iron and heater.