Which gas is obtained on dissolving zinc is not dilute nitric acid?

Options

A. `NH_3`
B. `NO_2`
C. `NO`
D. `N_2O`

Answer

To solve the question, "Which gas is obtained on dissolving zinc in dilute nitric acid?", we need to analyze the reaction between zinc and dilute nitric acid.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this scenario are zinc (Zn) and dilute nitric acid (HNO3).

2. **Understand the Reaction**:
- When zinc reacts with dilute nitric acid, it typically produces zinc nitrate (Zn(NO3)2), water (H2O), and a gas.

3. **Determine the Gas Produced**:
- In the case of dilute nitric acid, the gas produced is nitrogen dioxide (NO2). This gas is a brown toxic gas that is formed during the reaction.

4. **Identify Gases Not Produced**:
- It is important to note that other gases such as nitrogen monoxide (NO), nitrous oxide (N2O), and ammonia (NH3) are not produced in this reaction with dilute nitric acid.

5. **Conclusion**:
- Therefore, the gas that is obtained when zinc is dissolved in dilute nitric acid is nitrogen dioxide (NO2), while nitrogen monoxide (NO), nitrous oxide (N2O), and ammonia (NH3) are gases that are not produced.

### Final Answer:
The gas obtained on dissolving zinc in dilute nitric acid is nitrogen dioxide (NO2), while nitrogen monoxide (NO), nitrous oxide (N2O), and ammonia (NH3) are not obtained.