Q.
Assertion : Phenol is more reactive than benzene towards electrophilic substitution reaction.
Reason : In the case of phenol, the intermediate carbocation is more resonance stabilised.
Solution:
Phenol is more reactive than benzene towards electrophilic substitution reaction. The donation of the oxygen's lone pair into the ring system increases the electron density around the ring. That makes the ring much more reactive than it is in benzene. The intermediate carbocation is more resonance stabilized.
