Choose the correct statement regarding the catalytic coverters.

Options

A. Motor vehicles equipped with catalytic converter should use leaded petrol
B. Catalytic converters have expensive metals namely platinum-palladium and rhodium as catalyst
C. Catalytic converters help in reducing particulate matter
D. As the exhaust passes through the catalytic converter nitrogen gas is Converted to nitric oxide

Explanation

To solve the question regarding catalytic converters, we will analyze each option provided and determine which statement is correct.

### Step-by-Step Solution:

1. **Analyze Option A**:
- The statement claims that motor vehicles equipped with catalytic converters should use leaded petrol.
- **Evaluation**: This is incorrect. Motor vehicles with catalytic converters must use lead-free petrol because lead can poison the catalysts and render them ineffective.

2. **Analyze Option B**:
- The statement claims that catalytic converters have expensive metals namely platinum, palladium, and rhodium as catalysts.
- **Evaluation**: This statement is correct. Catalytic converters utilize these precious metals to facilitate the chemical reactions needed to reduce harmful emissions.

3. **Analyze Option C**:
- The statement claims that catalytic converters help in reducing particulate matter.
- **Evaluation**: This is incorrect. While catalytic converters primarily reduce harmful gases (like CO, NOx, and unburned hydrocarbons), they are not specifically designed to reduce particulate matter.

4. **Analyze Option D**:
- The statement claims that as the exhaust passes through the catalytic converter, nitrogen gas is converted to nitric oxide.
- **Evaluation**: This is incorrect. In reality, nitric oxide (NO) is converted back to nitrogen gas (N2) in the catalytic converter.

5. **Conclusion**:
- After evaluating all options, the only correct statement is Option B: "Catalytic converters have expensive metals namely platinum, palladium, and rhodium as catalysts."

### Final Answer:
The correct statement regarding catalytic converters is Option B: "Catalytic converters have expensive metals namely platinum, palladium, and rhodium as catalysts."

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