question_answer

Towards electrophilic substitution, the most reactive will be

A) Nitrobenzene

B) Aniline

C) Aniline hydrochloride

D) N-Acetylaniline

Correct Answer: B

Solution :

[b]

Nitrobenzene

Aniline

Aniline hydrochloride

N-Acetylaniline

Nitrobenzene and aniline hydrochloride have electron- withdrawing (\[-N{{O}_{2}}\] and \[-\overset{+}{\mathop{N}}\,{{H}_{3}}\]) groups, hence these will undergo electrophilic substitution with difficulty. Aniline and N- acetylaniline (acetanilide) have electron- releasing groups, however \[-NHCOC{{H}_{3}}\] is less electron- releasing than \[-N{{H}_{2}}\] due to delocalisation of lone pair of electron on N toward carbonyl group. Hence aniline (having\[-N{{H}_{2}}\]) will undergo electrophilic substitution most easily.