Which of the following does not give `NO_(2)` by heating at `500^(circ)C` ?

Options

A. `NaNO_(3)`
B. `Pb(NO_(3))_(2)`
C. `Cu(NO_(3))_(2)`
D. `AgNO_(3)`

Explanation

To determine which of the following compounds does not produce nitrogen dioxide (NO₂) when heated to 500°C, we will analyze each option one by one based on their thermal decomposition reactions.

### Step-by-Step Solution:

1. **Analyze Sodium Nitrate (NaNO₃)**:
- When sodium nitrate is heated, it decomposes as follows:
\[ 2 \text{NaNO}_3 \rightarrow 2 \text{NaNO}_2 + \text{O}_2 \]
- **Conclusion**: Sodium nitrate does not produce NO₂ upon heating.

2. **Analyze Lead Nitrate (Pb(NO₃)₂)**:
- The decomposition reaction for lead nitrate is:
\[ 2 \text{Pb(NO}_3)_2 \rightarrow \text{PbO} + 4 \text{NO}_2 + \text{O}_2 \]
- **Conclusion**: Lead nitrate produces NO₂ upon heating.

3. **Analyze Copper Nitrate (Cu(NO₃)₂)**:
- The decomposition reaction for copper nitrate is:
\[ 2 \text{Cu(NO}_3)_2 \rightarrow 2 \text{CuO} + 4 \text{NO}_2 + \text{O}_2 \]
- **Conclusion**: Copper nitrate produces NO₂ upon heating.

4. **Analyze Silver Nitrate (AgNO₃)**:
- The decomposition reaction for silver nitrate is:
\[ 2 \text{AgNO}_3 \rightarrow 2 \text{Ag} + 2 \text{NO}_2 + \text{O}_2 \]
- **Conclusion**: Silver nitrate produces NO₂ upon heating.

### Final Conclusion:
After analyzing all options, we find that **sodium nitrate (NaNO₃)** is the only compound that does not produce nitrogen dioxide (NO₂) when heated to 500°C. Therefore, the correct answer is:

**Option A: Sodium Nitrate (NaNO₃)**