The gas/es involved in the formation of photochemical fog are

Options

A. `CO_(2)`
B. `SO_(2)`
C. NO
D. none of these

Answer

To answer the question regarding the gases involved in the formation of photochemical fog, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding Photochemical Fog**:
- Photochemical fog, often referred to as photochemical smog, is a type of air pollution that is formed when sunlight reacts with pollutants in the atmosphere.

2. **Identifying Primary Pollutants**:
- Primary pollutants are those that are emitted directly from a source. In the case of photochemical fog, the primary pollutants include:
- **Nitric Oxide (NO)**
- **Nitrogen Dioxide (NO2)**
- **Volatile Organic Compounds (VOCs)**

3. **Identifying Secondary Pollutants**:
- Secondary pollutants are formed when primary pollutants undergo chemical reactions in the atmosphere. The main secondary pollutant involved in photochemical fog is:
- **Ozone (O3)**

4. **Chemical Reactions**:
- The formation of ozone involves a series of reactions:
- Nitrogen dioxide (NO2) reacts with sunlight to produce nitric oxide (NO) and oxygen (O2).
- The oxygen (O2) then reacts with other oxygen atoms (O) produced in the reaction to form ozone (O3).

5. **Conclusion**:
- The gases involved in the formation of photochemical fog are:
- Primary Pollutants: Nitric Oxide (NO), Nitrogen Dioxide (NO2), and Volatile Organic Compounds (VOCs).
- Secondary Pollutant: Ozone (O3).

### Final Answer:
The gases involved in the formation of photochemical fog are Nitric Oxide (NO), Nitrogen Dioxide (NO2), Volatile Organic Compounds (VOCs), and Ozone (O3).

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