Question

Rank in the order of increasing acidity.

• A. $III<I<II$
• B. $I<III<II$
• C. $III<II<I$
• D. $II<I<III$

Answer 1

The correct option is D $II<I<III$

Phenol will be the most acidic as the phenoxide ion is stabilized by resonance. Among $I$ and $II$, $I$ will be more acidic. This is because after the removal of proton, negative charge on oxygen is more stable than that on nitrogen owing to oxygen's more electronegative nature.

Hence, the correct acidity order is- $II<I<III$