Answer: 1°, 2°, 3° aliphatic amines.
- A 1°, 2°, 3° aliphatic amines
- B 3°, 2°, 1° aliphatic amines in that order
- C 2°, 1°, 3° aliphatic amines in that order
- D All three classes release N<sub>2</sub> gas equally
Correct answer: A. 1°, 2°, 3° aliphatic amines
Explanation: 1° aliphatic → N<sub>2</sub>; 2° → N-nitrosamine; 3° → no reaction with HNO<sub>2</sub>.
In aniline, the nitrogen's lone pair is pulled into the benzene ring through resonance, leaving less electron density available to accept a proton - which is why aniline is a much weaker base than methylamine, where the lone pair is fully available.
Concept context
Nitrogen-containing organic compounds. Covers classification (primary, secondary, tertiary), basicity comparison, preparation methods, and reactions including diazotization and coupling, key for understanding dyes and pharmaceuticals.