Question

7.The major product(s) in the following reaction is (are) CH,CH CH, CH OH OCH CHy OCHy CH,CH CHy CH,CH [A] Only1 (B) Only 1IC) A racemic mixture of [1) and [I) D] None of these s. Which of the following represents the order of solvents in increasing polarity from left to A) methanol, acetone, ethyl acetate, hexanes C) acetone, hexanes, methanol, ethyl acetate D) ethyl acetate, methanol, hexanes, acetone 9. In Thin Layer Chromatography (TLC) Re stands for A) Rate factor B) Refractive Index C) Retardation factor D) None of the above 1O. Which of the following statements is(are) true? A) If a polar compound moves too slowly in a non-polar solvent, switching to a more polar solvent will cause the compound to move faster B) If a non polar compound moves too fast on a TLC plate switching to a less polar solvent will cause the compound to move slower C) The polarity of a solvent system can be varied by mixing two solvents together D) All of the above 11. An experiment resulted in the generation of approximately 30 mL of organic waste, whicl is mostly chloroform CHCl. The correct method of disposal of this waste is to: A) Carefully pour it down the sink and subsequently flush with cold water B) Allow it to sit for a while in the fume hood for complete evaporation C) Pouring the material into a waste container designated for halogenated wastes. D) None of these

Answer 1

Q8

the polarity :

methanol > acetone (since methanol has OH gruop which is very polar, acetone has 3carbon:1 oxygen ratio, not that polar)

Ethyl acetate > hexane (ethyl acetate has oxygen, can have som dipole formation, hexane has 0 carbon-Oxygne raito)

then

hexane < Ethyl acetate < aceonte < methanol

Q9

TLC stands for Thin Layer Chromatography; it is an analytical technique in which we exploit each sample's affinity toward different polar/nonpolar solvents.

Typically, we allow the mobile phase to go up to the "Rfinal" mark, or final reference. This is the distance travelled by the solvent (mobile phase). It starts at solvent level, it is R0, therefore.

Rf = distance traveled by sample / distance traveled by solvent

therefore

none is listed

Q10

a --> false, we must swith to a nonpolar species

b --> false, we msut swith to a much polar species

c --> true

Q11

this is carcinoger, then

the best option is --> C, the halogenated wastes