When acetamide is treated with `HNO_(2)`, the gas is evolved

Options

A. `H_(2)`
B. `O_(2)`
C. `N_(2)`
D. `CH_(4)`

Explanation

To solve the problem of what gas is evolved when acetamide is treated with HNO₂, we can follow these steps:

### Step 1: Identify the reactants
Acetamide is a compound with the formula CH₃C(=O)NH₂. When it reacts with nitrous acid (HNO₂), we need to understand the nature of this reaction.

**Hint:** Acetamide is an amide, and it reacts with nitrous acid to produce nitrogen gas.

### Step 2: Write the reaction
When acetamide reacts with HNO₂, it undergoes a process called deamination. The reaction can be represented as follows:

\[ \text{CH}_3C(=O)NH_2 + HNO_2 \rightarrow \text{CH}_3C(=O) + N_2 + H_2O \]

In this reaction, the amide group (-NH₂) is converted into nitrogen gas (N₂), and water is also produced.

**Hint:** Look for the conversion of the amine group to nitrogen gas.

### Step 3: Identify the products
From the reaction, we see that nitrogen gas (N₂) is one of the products formed. The other product is an intermediate compound, which can be a carbonyl compound.

**Hint:** Focus on the gaseous product that is released during the reaction.

### Step 4: Conclusion
The gas that is evolved when acetamide is treated with HNO₂ is nitrogen gas (N₂).

**Final Answer:** The gas evolved is nitrogen gas (N₂).

### Summary of Steps:
1. Identify acetamide and nitrous acid as reactants.
2. Write the reaction showing the conversion of acetamide to nitrogen gas.
3. Identify nitrogen gas as the product.
4. Conclude that nitrogen gas is evolved in the reaction.