Q.Assertion: Phenol is more reactive than benzene towards electrophilic substitution reaction.
Reason: In the case of phenol, the intermediate arenium ion is more stabilized by resonance.

Step 1. Assertion: phenol IS more reactive than benzene toward electrophilic aromatic substitution -- TRUE, since its -OH group donates electron density into the ring by resonance, making the ring more nucleophilic overall.

Step 2. Reason: in phenol's electrophilic substitution, the intermediate arenium (Wheland) cation IS more stabilised by resonance than benzene's corresponding intermediate -- TRUE, because one of the resonance structures of phenol's arenium ion places the positive charge directly on the oxygen-bearing carbon, where it is further delocalised onto the oxygen's lone pair, an option benzene's plain arenium ion never has. …

Confirm phenol's greater ring reactivity is a settled fact (section 11.16), then check that the resonance-stabilised arenium-io …

• Assuming 'more reactive' assertions about phenol always trace back to ground-state stability rather than to the STABILITY OF THE INTERMEDIATE formed during the reacti …