A colourless , odourless and non - combustible gas is liberated when ethylamine reacts with :

Options

A. NaOH
B. `CH_3 COCl`
C. `NaNO_2 +HCI`
D. `H_2SO_4`

Answer

To solve the question regarding the liberation of a colorless, odorless, and non-combustible gas when ethylamine reacts with certain compounds, we will analyze the reactions step by step.

### Step-by-Step Solution:

1. **Identify Ethylamine**:
Ethylamine is represented by the formula \( \text{C}_2\text{H}_5\text{NH}_2 \) or \( \text{CH}_3\text{CH}_2\text{NH}_2 \). It is an amine and behaves as a weak base.

**Hint**: Remember that ethylamine has a basic nature due to the presence of the amino group.

2. **Consider the Reactions**:
We need to evaluate the possible reactions of ethylamine with the given compounds to determine which one produces a gas that is colorless, odorless, and non-combustible.

3. **Reaction with NaOH**:
Ethylamine does not react with sodium hydroxide (NaOH) as both are bases. No gas is produced in this reaction.

**Hint**: Base + Base reactions typically do not produce gases.

4. **Reaction with Acyl Chloride (e.g., CH3COCl)**:
When ethylamine reacts with an acyl chloride, it forms an amide and hydrochloric acid (HCl). This reaction does not produce a gas.

**Hint**: Acyl chlorides react with amines to form amides and release HCl, which is a liquid.

5. **Reaction with Sodium Nitrite and Hydrochloric Acid (NaNO2 + HCl)**:
This is a key reaction. Ethylamine reacts with sodium nitrite in the presence of hydrochloric acid to form a diazonium salt. The reaction proceeds as follows:
- Ethylamine reacts with NaNO2 and HCl to form a diazonium ion.
- The diazonium ion can lose nitrogen gas (N2), which is colorless, odorless, and non-combustible.

**Hint**: Look for reactions that involve diazotization, as they often produce nitrogen gas.

6. **Reaction with Sulfuric Acid (H2SO4)**:
Ethylamine reacts with sulfuric acid to form ethylammonium sulfate. This reaction does not produce any gas.

**Hint**: Strong acids typically protonate amines to form ammonium salts, not gases.

7. **Conclusion**:
The only reaction that produces a colorless, odorless, and non-combustible gas is the reaction of ethylamine with sodium nitrite and hydrochloric acid, which liberates nitrogen gas (N2).

### Final Answer:
The colorless, odorless, and non-combustible gas liberated when ethylamine reacts with sodium nitrite and hydrochloric acid is nitrogen gas (N2).