Question

Carboxylic acids are more acidic than phenol and alcohol because of:

• A. intermolecular hydrogen bonding
• B. formation of dimers
• C. highly acidic hydrogen
• D. resonance stabilization of their conjugate base

Hint:

The acidity of carboxylic acids is due to the resonance stabilization of their conjugate base, which delocalizes the negative charge over two oxygen atoms.

Answer 1

The Correct Option is D

Step 1: Carboxylic acids are more acidic than phenols and alcohols because they can stabilize the negative charge on the conjugate base through resonance. In the conjugate base of a carboxylate ion (\( {RCOO}^- \)), the negative charge is delocalized over the two oxygen atoms.
Step 2: This resonance stabilization makes the carboxylate ion more stable, which in turn makes the acid (carboxylic acid) more likely to lose a proton (H\(^+\)) and thus more acidic.
Step 3: Phenols and alcohols do not have the same level of resonance stabilization for their conjugate bases, so they are less acidic compared to carboxylic acids.