`N_(2)` gas will not be evolved upon reaction of `HNO_(2)` with which of the following amines ?

Options

A. `1^(@)`
B. `2^(@)`
C. `3^(@)`
D. Both (2) & (3)

Explanation

To determine which amine will not evolve nitrogen gas (N₂) upon reaction with nitrous acid (HNO₂), we need to analyze the reactions of different types of amines with HNO₂.

### Step-by-Step Solution:

1. **Identify the Types of Amines**:
- Amines can be classified into three categories: primary (1°), secondary (2°), and tertiary (3°) amines.
- General structures:
- Primary amine: RNH₂
- Secondary amine: R₂NH
- Tertiary amine: R₃N

2. **Reaction of Primary Amines with HNO₂**:
- When a primary amine (RNH₂) reacts with HNO₂, it forms a diazonium salt, which is unstable and decomposes to release nitrogen gas (N₂).
- Reaction:
\[ RNH_2 + HNO_2 \rightarrow R-N_2^+ + H_2O \rightarrow R + N_2 + H_2O \]
- Conclusion: N₂ gas is evolved.

3. **Reaction of Secondary Amines with HNO₂**:
- When a secondary amine (R₂NH) reacts with HNO₂, it forms a nitrosamine, which does not decompose to release nitrogen gas.
- Reaction:
\[ R_2NH + HNO_2 \rightarrow R_2N-O-N=O \]
- Conclusion: N₂ gas is NOT evolved.

4. **Reaction of Tertiary Amines with HNO₂**:
- Tertiary amines (R₃N) do not react with HNO₂ to form a stable product that releases nitrogen gas.
- Reaction:
\[ R_3N + HNO_2 \rightarrow \text{No reaction leading to N}_2 \]
- Conclusion: N₂ gas is NOT evolved.

5. **Final Analysis**:
- From the above reactions, we conclude:
- Primary amines evolve N₂.
- Secondary and tertiary amines do NOT evolve N₂.
- Therefore, the answer to the question is that N₂ gas will not be evolved upon reaction of HNO₂ with secondary and tertiary amines.

### Conclusion:
The amines that will not evolve N₂ gas upon reaction with HNO₂ are **secondary (2°) and tertiary (3°) amines**.