Photochemical smog is actually a cause of pollution of

Options

A. Soil
B. Air
C. Noise
D. Water

Answer

**Step-by-Step Solution:**

1. **Understanding Photochemical Smog**: Photochemical smog is a type of air pollution that occurs when sunlight reacts with pollutants such as nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the atmosphere. This reaction leads to the formation of secondary pollutants, including ozone (O3).

2. **Formation of Photochemical Smog**: The process begins when ultraviolet (UV) light from the sun interacts with nitrogen dioxide (NO2). This interaction causes a photolysis reaction, where NO2 breaks down into nitric oxide (NO) and a nascent oxygen atom (O).

- **Chemical Reaction**:
\[ \text{NO}_2 + \text{UV light} \rightarrow \text{NO} + \text{O} \]

3. **Ozone Formation**: The nascent oxygen (O) produced in the previous step reacts with molecular oxygen (O2) present in the atmosphere to form ozone (O3).

- **Chemical Reaction**:
\[ \text{O} + \text{O}_2 \rightarrow \text{O}_3 \]

4. **Reactions Involving Ozone**: Ozone is a powerful oxidizing agent and can react with nitric oxide (NO) to regenerate nitrogen dioxide (NO2) and oxygen (O2).

- **Chemical Reaction**:
\[ \text{NO} + \text{O}_3 \rightarrow \text{NO}_2 + \text{O}_2 \]

5. **Characteristics of Photochemical Smog**: Photochemical smog is typically observed as a brown haze, especially in urban areas during the morning hours. It is more prevalent in cold and humid climates.

6. **Conclusion**: Photochemical smog is primarily a cause of air pollution, resulting from the complex interactions between sunlight and various pollutants in the atmosphere.