How can photochemical smog be controlled?

Options

A. By using catalytic convertors in the automobiles/industry.
B. By complete combustion of fuel
C. By using catalyst.
D. By using tall chimneys

Answer

**Step-by-Step Solution:**

1. **Understanding Photochemical Smog:**
- Photochemical smog is a type of air pollution that is formed when sunlight reacts with pollutants such as nitrogen oxides (NOx) and volatile organic compounds (VOCs). This reaction leads to the formation of secondary pollutants, including ozone, which contribute to smog.

2. **Identifying Sources of Pollutants:**
- The primary sources of nitrogen oxides and carbon monoxide include vehicle emissions, industrial discharges, and combustion processes. These pollutants are key contributors to the formation of photochemical smog.

3. **Control Measures:**
- To control photochemical smog, we can implement several strategies:
- **Using Catalytic Converters:**
- Catalytic converters are devices installed in automobiles and industrial exhaust systems. They facilitate chemical reactions that convert harmful pollutants like nitrogen oxides into nitrogen gas (N2) and carbon monoxide into carbon dioxide (CO2). This reduces the amount of smog-forming pollutants released into the atmosphere.
- **Complete Combustion of Fuels:**
- While complete combustion of fuels reduces the formation of carbon monoxide and unburned hydrocarbons, it does not eliminate nitrogen oxides, which can still contribute to smog formation. Therefore, this method alone is not sufficient to control photochemical smog.
- **Using Catalysts:**
- While catalysts can help in various chemical reactions, they do not directly control photochemical smog unless they are part of a catalytic converter system.
- **Tall Chimneys:**
- Tall chimneys can disperse pollutants over a larger area, but they do not eliminate the pollutants. This can lead to the formation of smog at different locations rather than controlling it.

4. **Conclusion:**
- The most effective method to control photochemical smog is the use of catalytic converters in vehicles and industries, as they significantly reduce the emissions of harmful pollutants that contribute to smog formation.

**Final Answer:**
Photochemical smog can be controlled primarily by using catalytic converters in automobiles and industries, which convert harmful pollutants into less harmful substances.

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