Answer: LiAlH4.
- A LiAlH4
- B NaBH4
- C HCl
- D KMnO4
Correct answer: A. LiAlH4
Explanation: LiAlH4 reduces nitriles to primary amines (RCN → RCH2NH2).
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.