Previous Year NEET Question- Haloalkanes L-4

Question: Which of the following undergoes nucleophilic substitution exclusively by $\mathrm{S}_{\mathrm{N}} 1$ mechanism?#

A) Ethyl chloride

B) Isopropyl chloride is an incorrect name; the correct name is 2-chloropropane.

C) Chlorobenzene

D) Benzyl chloride

Answer: Benzyl chloride#

Sol:#

$\mathrm{S}_{\mathrm{N}} 1$ reaction is favoured by bulky groups on the carbon atom attached to halogens and nature of carbonium ion in substrate is

Benzyl $>$ Allyl $>$ Primary $>$ Secondary $>$ Tertiary $>$ Methyl halides.