When a lead salt is heated with sodium carbonate in charcoal cavity it gives

Options

A. yellow incrustation
B. brown
C. black
D. blue

Answer

To solve the question "When a lead salt is heated with sodium carbonate in a charcoal cavity, it gives what?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Lead Salt**:
- A common lead salt is lead nitrate, which has the formula \( \text{Pb(NO}_3\text{)}_2 \).

2. **Reaction with Sodium Carbonate**:
- When lead nitrate is heated with sodium carbonate (\( \text{Na}_2\text{CO}_3 \)), a double displacement reaction occurs.
- The products of this reaction are lead carbonate (\( \text{PbCO}_3 \)) and sodium nitrate (\( \text{NaNO}_3 \)).
- The balanced reaction can be written as:
\[ \text{Pb(NO}_3\text{)}_2 + \text{Na}_2\text{CO}_3 \rightarrow \text{PbCO}_3 + 2\text{NaNO}_3 \]

3. **Decomposition of Lead Carbonate**:
- Upon further heating, lead carbonate decomposes into lead oxide (\( \text{PbO} \)) and carbon dioxide (\( \text{CO}_2 \)):
\[ \text{PbCO}_3 \rightarrow \text{PbO} + \text{CO}_2 \]

4. **Heating in Charcoal Cavity**:
- When lead oxide (\( \text{PbO} \)) is heated in the presence of charcoal (carbon), it reduces to lead (\( \text{Pb} \)) and produces carbon monoxide (\( \text{CO} \)):
\[ \text{PbO} + \text{C} \rightarrow \text{Pb} + \text{CO} \]

5. **Final Product**:
- The lead produced in this reaction is known as "bead" and is often associated with a yellow incrustation.

### Conclusion:
- Therefore, when a lead salt is heated with sodium carbonate in a charcoal cavity, it gives a yellow incrustation of lead.

### Answer:
- The correct option for this question is **Option A: Yellow incrustation**.