When lead nitrate is heated emission of ..... occurs.

Options

A. `N_(2)O_(3)`
B. `NO_(2)`
C. NO
D. `N_(2)`

Explanation

To solve the question "When lead nitrate is heated, emission of ..... occurs," we will follow these steps:

### Step 1: Understand the Composition of Lead Nitrate
Lead nitrate has the chemical formula \( \text{Pb(NO}_3\text{)}_2 \). It consists of lead (Pb) and nitrate ions (NO3).

**Hint:** Remember the chemical formula of lead nitrate to understand its components.

### Step 2: Write the Thermal Decomposition Reaction
When lead nitrate is heated, it undergoes thermal decomposition. The balanced chemical equation for this reaction is:

\[ 2 \text{Pb(NO}_3\text{)}_2 \rightarrow 2 \text{PbO} + 4 \text{NO}_2 + \text{O}_2 \]

This means that two moles of lead nitrate decompose to form two moles of lead oxide (PbO), four moles of nitrogen dioxide (NO2), and one mole of oxygen gas (O2).

**Hint:** Look for the products formed during the decomposition of lead nitrate when heated.

### Step 3: Identify the Gases Emitted
From the balanced equation, we can see that the gases emitted during the heating of lead nitrate are:

- Nitrogen dioxide (NO2)
- Oxygen (O2)

**Hint:** Focus on the gaseous products to answer the question.

### Step 4: Determine the Correct Answer
The question asks specifically for the emission that occurs when lead nitrate is heated. Among the gases produced, nitrogen dioxide (NO2) is a notable product.

**Hint:** If the question provides multiple choices, look for NO2 as a key product.

### Conclusion
Thus, when lead nitrate is heated, the emission of nitrogen dioxide (NO2) occurs.

**Final Answer:** NO2