Which of the following will give `N_(2)` gas on treatment with nitrous acid `(NaNO_(2)+HCl)` ?

Options

A. `C_(2)H_(5)NH_(2)`
B. `CH_(3)NH_(2)`
C. `(CH_(3))_(2)CH-NH_(2)`
D. All will give `N_(2)`

Explanation

To determine which of the given compounds will produce nitrogen gas (N₂) when treated with nitrous acid (NaNO₂ + HCl), we need to analyze the behavior of primary amines in this reaction.

### Step-by-Step Solution:

1. **Identify the Type of Amines**:
- The question provides four options, all of which are primary amines. Primary amines have the general structure RNH₂, where R is an alkyl or aryl group.

2. **Understanding the Reaction with Nitrous Acid**:
- When primary amines react with nitrous acid (HNO₂), they undergo a reaction that leads to the formation of nitrogen gas (N₂) and an alcohol. The general reaction can be represented as:
\[ RNH_2 + HNO_2 \rightarrow R-OH + N_2 + H_2O \]
- This reaction is specific to primary amines; secondary and tertiary amines do not produce nitrogen gas under these conditions.

3. **Evaluate Each Option**:
- **Option 1**: CH₂CH₃NH₂ (ethylamine) - This is a primary amine.
- **Option 2**: CH₃NH₂ (methylamine) - This is also a primary amine.
- **Option 3**: (CH₃)₂CHNH₂ (isopropylamine) - This is a primary amine as well.
- **Option 4**: All the above options are primary amines.

4. **Conclusion**:
- Since all the options provided are primary amines, they will all react with nitrous acid to produce nitrogen gas (N₂).

5. **Final Answer**:
- Therefore, all of the given options will give N₂ gas on treatment with nitrous acid.