`H_(2)O_(2)` restores the colour of old lead paintings, blackened by the action of `H_(2)S` gas by :

Options

A. Converting `PbO_(2)` to Pb
B. Oxidising pbS to `PbSO_(4)`
C. Converting `PbCO_(3)` to Pb
D. Oxidising `PbSO_(3) to PbSO_(4)`

Answer

To solve the question of how hydrogen peroxide restores the color of old lead paintings blackened by the action of hydrogen sulfide (H₂S) gas, we can break down the process step by step.

### Step-by-Step Solution:

1. **Understanding the Problem**:
- Old lead paintings turn black due to the formation of lead sulfide (PbS) when lead reacts with hydrogen sulfide (H₂S) gas.
- The black color is due to the presence of lead sulfide.

2. **Identifying the Reaction**:
- To restore the color of the painting, we need to convert lead sulfide (PbS) back to a compound that does not have the black color.
- Hydrogen peroxide (H₂O₂) can be used for this purpose as it can act as an oxidizing agent.

3. **Chemical Reaction**:
- The reaction we are interested in is the oxidation of lead sulfide (PbS) by hydrogen peroxide (H₂O₂).
- The balanced chemical equation for this reaction is:
\[ PbS + 4H₂O₂ \rightarrow PbSO₄ + 4H₂O \]
- In this reaction, lead sulfide (PbS) is oxidized to lead sulfate (PbSO₄), and water (H₂O) is produced.

4. **Oxidation States**:
- In lead sulfide (PbS), the oxidation state of sulfur is -2.
- In lead sulfate (PbSO₄), the oxidation state of sulfur is +6.
- This change in oxidation state indicates that sulfur is being oxidized.

5. **Conclusion**:
- The process of restoring the color of the paintings involves the oxidation of lead sulfide (PbS) to lead sulfate (PbSO₄) using hydrogen peroxide (H₂O₂).
- Therefore, the correct answer to the question is: **Oxidizing lead sulfide to lead sulfate**.

### Final Answer:
The correct option is: **Oxidizing lead sulfide to lead sulfate**.

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