question_answer

Arrange the following alcohols in the increasing order o reactivity with HBr.

(I) benzyl alcohol

(II) p-methyl benzyl alcohol

(III) p-nitrobenzyl alcohol

(IV) p-chlorobenzyl alcohol

A) I<II<III<IV      

B) III<IV<I<II

C) II<I<IV<III      

D) IV<II<II<I

Correct Answer: B

Solution :

[b] Reactive intermediate carbocation is involved, hence greater the stability of carbocation, greater the reactivity of corresponding alcohols. Stability order = B > A > D > C Reactivity = II > I > IV > III