Question

Which of the following compounds will give racemic mixture on nucleophilic substitution by $O{H}^{-}$ ion?

(a) (i) (b) (i), (ii) and (iii) (c) (ii) and (iii) (d) (i) and (iii)

Answer 1

A mixture containing the enantiomers in equimolar amount have zero optical rotation, as the rotation due to one isomer cancelled by the rotation due to other isomer. Such a mixture is known aa s racemic mixture. All those compounds which follow $S_{N}2$ mechanism during nucleophilic substitution reaction form a racemic mixture.

Order of reactivity of alkyl halides towards $S_{N}1$.

and reactions as follows:

Tertiary halide; secondary halide; primary halide; $C{H}_{3}X.$

For $S_{N}1$ reaction.

Thus, contains a chiral carbon and gives a racemic product.

Hence, option (a) is correct.