Question

Answer the following:
(i) Haloalkanes easily dissolve in organic solvents, why?
(ii) What is known as a racemic mixture? Give an example.

(iii) Of the two bromoderivatives, C₆H₅CH(CH₃)Br and C₆H₅CH(C₆H₅)Br, which one is more reactive in S_N1 substitution reaction and why?

Answer 1

(i) Haloalkanes dissolve in organic solvents because the new intermolecular attractions between haloalkanes and organic solvent molecules have much the same strength as ones being broken in the separate haloalkanes and solvent molecules.
(ii) An equimolar mixture of a pair of enantiomers is called racemic mixture. For example, butan-2-ol. A racemic mixture is optically inactive due to external compensation.

(iii) Of the two bromo derivatives, C₆H₅CH(CH₃)Br and C₆H₅CH(C₆H₅)Br, the intermediate obtained from C₆H₅CH (C₆H₅) Br is more stable than obtained from C₆H₅CH(CH₃) Br because it is stabilised by two phenyl groups due to resonance. Therefore, C₆H₅CH (C₆H₅)Br is more reactive than C₆H₅(CH₃) Br.