Answer: Hinsberg's reagent (benzenesulfonyl chloride).
- A Hinsberg's reagent (benzenesulfonyl chloride)
- B Lucas reagent, used instead to distinguish primary, secondary, and tertiary alcohols
- C Tollens' reagent, used instead to distinguish aldehydes from ketones
- D Fehling's solution, used instead to detect reducing sugars and aldehydes
Correct answer: A. Hinsberg's reagent (benzenesulfonyl chloride)
Explanation: Hinsberg's reagent (C6H5SO2Cl) reacts differently with primary, secondary, and tertiary amines.
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.