Answer: zero.
- A three
- B one
- C two
- D zero
Correct answer: D. zero
Explanation: In a tertiary amine all three positions on nitrogen carry alkyl or aryl groups, leaving no N-H bond.
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.