Question

The nucleophilic addition reactions of aldehydes are carried out in ________ medium.

(a) neutral

(b) acidic

(c) weakly basic

(d) extremely basic

This question was addressed to me in a national level competition.

This intriguing question comes from Aldehydes and Ketones Chemical Reactions in chapter Aldehydes, Ketones and Carboxylic Acids of Chemistry – Class 12

Answer 1

Correct answer is (b) acidic

Explanation: When the incoming nucleophile is weak, the acidic medium helps in protonation by increasing the positive charge on the carbonyl carbon so that it is more susceptible to attack by relatively weaker nucleophiles.