Which of the following on heating produces `NO_(2) ` ?

Options

A. NaNO3
B. AgNo3
C. Nh4NO3
D. Nh4NO2

Explanation

To solve the problem of which compound produces NO2 upon heating, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Compounds**: We have four compounds to analyze:
- NaNO3 (Sodium Nitrate)
- AgNO3 (Silver Nitrate)
- NH4NO3 (Ammonium Nitrate)
- NH4NO2 (Ammonium Nitrite)

2. **Analyze NaNO3**:
- When heated, NaNO3 decomposes as follows:
\[ 2 \text{NaNO}_3 \rightarrow 2 \text{NaNO}_2 + \text{O}_2 \]
- Further heating can lead to:
\[ 4 \text{NaNO}_3 \rightarrow \text{Na}_2\text{O} + 5 \text{O}_2 + \text{N}_2\text{O} \]
- **Conclusion**: No NO2 is produced from NaNO3.

3. **Analyze AgNO3**:
- When heated, AgNO3 decomposes as follows:
\[ 2 \text{AgNO}_3 \rightarrow 2 \text{Ag} + \text{O}_2 + 2 \text{NO}_2 \]
- **Conclusion**: NO2 is produced from AgNO3.

4. **Analyze NH4NO3**:
- When heated, NH4NO3 decomposes as follows:
\[ \text{NH}_4\text{NO}_3 \rightarrow \text{N}_2\text{O} + 2 \text{H}_2\text{O} \]
- **Conclusion**: No NO2 is produced from NH4NO3.

5. **Analyze NH4NO2**:
- When heated, NH4NO2 decomposes as follows:
\[ \text{NH}_4\text{NO}_2 \rightarrow \text{N}_2 + 2 \text{H}_2\text{O} \]
- **Conclusion**: No NO2 is produced from NH4NO2.

6. **Final Conclusion**:
- Among the four compounds, only AgNO3 produces NO2 upon heating.

### Answer:
The compound that produces NO2 upon heating is **AgNO3**.