Question

Which one of the following compounds has the most acidic nature?

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Answer 2

Presence of electron withdrawing substituent increases the acidity while electron releasing substituent, when present, decreases the acidity. Phenyl is an electron withdrawing substituent while $- CH_3$ is an electron releasing substituent. Moreover, phenoxide ion is more resonance stabilised as compared to benzyloxide ion, thus releases proton more easily. That's why phenol is a strong acid among the given compounds