Decolouration of lead and silver paints is caused due to

Options

A. sulphur dioxide
B. carbon monoxide
C. hydrogen sulphide
D. ozone

Answer

**Step-by-Step Solution:**

1. **Understand the Question:**
The question asks about the cause of decoloration in lead and silver paints. This involves identifying which substance reacts with these paints to cause them to lose their color.

2. **Identify the Options:**
The options provided are:
- a) Sulfur dioxide
- b) Carbon monoxide
- c) Hydrogen sulfide
- d) Ozone

3. **Analyze Each Option:**
- **Sulfur Dioxide (SO2):** While it can react with some materials, it is not primarily known for causing decoloration in paints.
- **Carbon Monoxide (CO):** This gas is primarily a pollutant and does not typically react with paints to cause decoloration.
- **Hydrogen Sulfide (H2S):** This gas is known to react with heavy metals, including those found in lead and silver paints, forming precipitates that lead to discoloration.
- **Ozone (O3):** Ozone can cause degradation in some materials but is not specifically known for causing decoloration in lead and silver paints.

4. **Conclusion:**
Based on the analysis, the correct answer is **c) Hydrogen sulfide**. This gas reacts with the heavy metal salts in the paints, leading to the formation of precipitates that cause the paint to lose its color.

5. **Final Answer:**
The decoloration of lead and silver paints is caused due to **hydrogen sulfide**.

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