Question

Assertion : Phenol is a weaker acid than ethanol.
Reason : Groups with $+M$ effect and $-I$ effect decrease acidity at $m$-position.

• A. If both assertion and reason are true and reason is a correct explanation of the assertion
• B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
• C. If the assertion is true but the reason is false
• D. If both the assertion and reason are false

Answer 1

Answer: (D)

Phenol is a stronger acid than the ethanol. This is due to the resonance stabilisaton of the phenolate ion which is produced after deprotonation.



But there is no such stabilisation in the case of ethanol

$C _{2} H _{5} OH \rightleftharpoons C _{2} H _{5} O ^{-}+ H ^{+}$

The groups with $+M$ and $-I$ effect decrease the acidity at pposition, but at m-position the acidity is increased due to $-I$ -effect.