Question

Which one of the following is used as a test for aliphatic primary amines?

• A. Tollen's test
• B. Fehling's test
• C. Isocyanide test
• D. Azo dye test
• E. Phthalein fusion test

Hint:

Only primary amines (not secondary or tertiary) give carbylamine test.

Answer 1

The Correct Option is C

Understanding the Concept: Aliphatic primary amines give carbylamine (isocyanide) test.

Step 1: Reaction involved. \[ RNH_2 + CHCl_3 + 3KOH \rightarrow RNC + 3KCl + 3H_2O \] Observation: A foul smelling isocyanide is formed.

Step 2: Analyze options.
• Tollen's test → aldehydes
• Fehling's test → aldehydes
• Isocyanide test → primary amines ✓
• Azo dye test → aromatic amines
• Phthalein test → phenols

Step 3: Final Answer. Only isocyanide test specifically identifies aliphatic primary amines. \[ \boxed{\text{Isocyanide test}} \]