Question

What type of amines exhibits diazotization reaction?

• A. Aliphatic primary amine
• B. Aromatic primary amine
• C. Aliphatic secondary amine
• D. Aromatic secondary amine

Hint:

Only primary aromatic amines give stable diazonium salts at low temperature.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
Diazotisation is the reaction of an amine with nitrous acid (\(\text{NaNO}_2+\text{HCl}\)) at 273-278 K to form a diazonium salt.

Step 2: Which amine
Primary aromatic amines such as aniline form arenediazonium salts, which are stable at low temperature because of resonance with the ring.

Step 3: Eliminate
Aliphatic primary amines give unstable diazonium salts that decompose to alcohols, and secondary amines give nitrosoamines.

Final Answer:
Aromatic primary amines undergo diazotisation. \[ \boxed{\text{(B) }\text{Aromatic primary amine}} \]