Answer: Do not react (no N-H bond).
- A Do not react (no N-H bond)
- B Form soluble salt
- C Form insoluble precipitate
- D Undergo oxidation
Correct answer: A. Do not react (no N-H bond)
Explanation: Tertiary amines have no N-H bond and so do not react with Hinsberg's reagent.
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.