`NO_(2)` can be prepared by heating :

Options

A. `NH_(4)NO_(3)`
B. `NaNO_(3)`
C. `Pb(NO_(3))_(2)`
D. `KNO_(3)`

Explanation

To solve the question of how to prepare \( \text{NO}_2 \) by heating, we can follow these steps:

### Step 1: Identify the substance to be heated
The question asks which substance can be heated to produce \( \text{NO}_2 \). Among the options provided, we need to identify the one that, upon heating, will yield \( \text{NO}_2 \).

### Step 2: Consider the thermal decomposition of lead nitrate
One common method to produce \( \text{NO}_2 \) is through the thermal decomposition of lead(II) nitrate (\( \text{Pb(NO}_3\text{)}_2 \)).

### Step 3: Write the balanced chemical equation
When lead(II) nitrate is heated, it decomposes according to the following reaction:
\[ \text{2Pb(NO}_3\text{)}_2 \rightarrow \text{2PbO} + \text{4NO}_2 + \text{O}_2 \]
In this reaction, lead(II) nitrate decomposes to form lead(II) oxide (\( \text{PbO} \)), nitrogen dioxide (\( \text{NO}_2 \)), and oxygen gas (\( \text{O}_2 \)).

### Step 4: Conclusion
From the reaction, we can see that heating lead(II) nitrate produces nitrogen dioxide as one of the products. Therefore, the correct answer to the question is that \( \text{NO}_2 \) can be prepared by heating lead(II) nitrate.

### Final Answer
The correct option is **C: Lead(II) nitrate**.

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