Question

The correct formula of Hinsberg's reagent is:

• A. C\(_6\)H\(_5\)COCl
• B. C\(_6\)H\(_5\)SO\(_2\)Cl
• C. C\(_6\)H\(_5\)CONHCH\(_3\)
• D. C\(_6\)H\(_6\)CH\(_2\)NH\(_2\)

Hint:

{Hinsberg Reagent = Benzenesulphonyl chloride} Formula to remember: \( C_6H_5SO_2Cl \)

Answer 1

The Correct Option is B

Concept:
Hinsberg's reagent is used in the
Hinsberg test to distinguish between primary, secondary, and tertiary amines. The reagent used is
benzenesulphonyl chloride. Formula: \[ C_6H_5SO_2Cl \]
Step 1: Recall the Hinsberg test.

• Primary amines → soluble sulphonamide (in alkali)
• Secondary amines → insoluble sulphonamide
• Tertiary amines → no reaction

Step 2: Identify correct formula.

• C\(_6\)H\(_5\)COCl → Benzoyl chloride (incorrect)
• C\(_6\)H\(_5\)SO\(_2\)Cl → Benzenesulphonyl chloride (correct)
• Others are unrelated compounds

\[ \therefore \text{Correct answer = (B)} \]