Question

Which of the following is most reactive towards electrophilic substitution reaction?

• A. Phenol
• B. Toluene
• C. Nitrobenzene
• D. Benzene

Answer 1

The correct option is A Phenol

The rate of electrophilic substitution reaction is directly proportional to nucleophilicity of benzene ring. The group which increase the electron density in benzene ring i.e. electron donating group increase the nucleophilicity of Benzene ring which results in an increase in the rate of reaction towards electrophilic substitution reaction.
In series of activating group $-OH$ comes first then $-C{H}_3$ hence, phenol is most reactive towards electrophilic substitution reaction.
$-N{O}_2$ group ring decativiting group thus it is less reactive toward electrophilic substitution.
between toluene and benzene, toluene is more reactive than benene toward electrophilic substitution beacause $-C{H}_3$ group being electron donating activate the ring toward electrophilic substitution
Hence the correct reactivity order toward electrophilic substitution reaction is phenol>toluene>benene>nitrobenene.