Air Pollution Control

Step 1: Understanding the Concept:
A catalytic converter is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction.

Step 3: Detailed Explanation:
Modern three-way catalytic converters perform three simultaneous tasks:
1. Reduction of nitrogen oxides (NO ) to nitrogen gas (N ): This is a reduction reaction. (e.g., ) 2. Oxidation of carbon monoxide (CO) to carbon dioxide (CO ): This is an oxidation reaction. (e.g., ) 3. Oxidation of unburnt hydrocarbons (HC) to carbon dioxide (CO ) and water (H O): This is also an oxidation reaction.
Therefore, the catalytic converter's main functions are the oxidation of CO and hydrocarbons, and the reduction of NO .

Step 4: Final Answer:
Catalytic converters are used for the oxidation of CO (and hydrocarbons) and the reduction of NO .

Step 1: Understanding the Concept:
The question asks to identify the device that is used for air pollution *monitoring* or *sampling*, rather than *control*.

Step 3: Detailed Explanation:

Step 4: Final Answer:
A High Volume Sampler is used for sampling air pollution, not for controlling it.