Answer: sp 3.
- A sp<sup>3</sup>
- B sp<sup>2</sup>
- C sp
- D sp<sup>3</sup>d
Correct answer: A. sp<sup>3</sup>
Explanation: Nitrogen in amines is sp<sup>3</sup> hybridised with a lone pair, giving a pyramidal geometry.
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.