Question

Assertion (A) Alcohols and water are weaker acids than phenols.
Reason (R) The delocalisation of negative charge makes the phenoxide ion more stable and favour the ionisation of phenol.

• A. Both A and $R$ are correct; $R$ is the correct explanation of $A$.
• B. Both A and $R$ are correct; $R$ is not the correct explanation of $A$.
• C. $A$ is correct; $R$ is incorrect.
• D. $R$ is correct; $A$ is incorrect.

Answer 1

Answer: (A)

The reaction of phenol with aqueous $NaOH$ indicates that phenols are stronger acids than alcohols and water.
The ionisation of an alcohol and a phenol takes place as follows

In alkoxide ion, the negative charge is localised on oxygen while in phenoxide ion, the charge is delocalised. The delocalisation of negative charge (structure I-V) makes phenoxide ion more stable and favours the ionisation of phenol.