Incorrect statement in the following is

Options

A. electrostatic precipitator can remove `99%` of particulate matter
B. scrubber can remove gases like `SO_(2)`
C. catalytic converters helps in reducing emission of poisonous gases
D. lead in petrol activates palladium and rhodium used in catalytic converters

Answer

To determine the incorrect statement from the options provided, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement A: Electrostatic precipitator can remove 99% of the particulate matter.**
- **Analysis:** This statement is true. Electrostatic precipitators are devices used to remove particulate matter from exhaust gases, especially in thermal power plants, and they can indeed remove up to 99% of particulate matter.

2. **Statement B: Scrubber can remove gases like SO2 (sulfur dioxide).**
- **Analysis:** This statement is also true. Scrubbers are designed to remove pollutants from gases, and they are particularly effective at removing sulfur dioxide from exhaust gases.

3. **Statement C: Catalytic converters help in reducing the emission of poisonous gases.**
- **Analysis:** This statement is true as well. Catalytic converters contain catalysts such as palladium and rhodium, which facilitate chemical reactions that convert harmful gases into less harmful emissions.

4. **Statement D: Lead in petrol activates palladium and rhodium used in catalytic converters.**
- **Analysis:** This statement is incorrect. In fact, lead acts as an inactivator of the catalysts (palladium and rhodium) in catalytic converters. The presence of lead can inhibit the function of these catalysts, leading to increased emissions of poisonous gases.

### Conclusion:
The incorrect statement is **Option D**: "Lead in petrol activates palladium and rhodium used in catalytic converters."

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