Question

Identify the reagent used to distinguish primary and secondary amines by Hinsberg test.

• A. \(\text{NaNO}_2\) and HCl
• B. \(\text{FeCl}_3\) (alc)
• C. \(\text{C}_6\text{H}_5\text{SO}_2\text{Cl}\)
• D. \(\text{CHCl}_3\) and KOH (alc)

Hint:

Hinsberg reagent is benzenesulfonyl chloride.

Answer 1

The Correct Option is C

Step 1: Approach
Recall the name of the test and the chemical it uses.

Step 2: Recall
Hinsberg's reagent is benzenesulfonyl chloride. It forms sulfonamides with primary and secondary amines, and the solubility of the product in alkali tells them apart.

Step 3: Conclusion
Option (C) is correct. The other three reagents belong to different tests: nitrous acid test, ferric chloride test and carbylamine test.

Final Answer:
Hinsberg's reagent is benzenesulfonyl chloride, option (C). \[ \boxed{\text{C}_6\text{H}_5\text{SO}_2\text{Cl}} \]