Which of the following statements about photochemical smog is not correct ?

Options

A. It occurs in warm , dry and sunny climate .
B. Chemically , it is a reducing mixture and is called reducing smog.
C. It is formed as a result of action of sunlight on unsaturated hyfrocarbons and nitrogen oxides .
D. It has high cncentration of oxidising agents and is also called oxidising smog.

Explanation

To determine which statement about photochemical smog is not correct, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understand Photochemical Smog**:
- Photochemical smog is formed when sunlight reacts with atmospheric pollutants such as nitrogen oxides and volatile organic compounds (VOCs). This reaction typically occurs in warm, sunny conditions.

2. **Review the Statements**:
- We need to evaluate each statement provided in the options to identify the incorrect one.

3. **Evaluate Option 1**:
- **Statement**: "It occurs in warm and dry and sunny climate."
- **Analysis**: This statement is correct. Photochemical smog is indeed prevalent in warm, dry, and sunny conditions.

4. **Evaluate Option 2**:
- **Statement**: "Chemically it is a reducing mixture and is called reducing smog."
- **Analysis**: This statement is incorrect. Photochemical smog is characterized by high concentrations of oxidizing agents, not reducing agents. Therefore, it is not referred to as reducing smog.

5. **Evaluate Option 3**:
- **Statement**: "It is formed as a result of action of sunlight on unsaturated hydrocarbons and nitrogen oxide."
- **Analysis**: This statement is correct. Photochemical smog is indeed formed through the action of sunlight on nitrogen oxides and hydrocarbons.

6. **Evaluate Option 4**:
- **Statement**: "It has high concentration of oxidizing agent and is also called oxidizing smog."
- **Analysis**: This statement is correct. Photochemical smog is associated with high levels of oxidizing agents, hence it can be referred to as oxidizing smog.

7. **Conclusion**:
- The incorrect statement about photochemical smog is **Option 2**: "Chemically it is a reducing mixture and is called reducing smog."

### Final Answer:
The statement that is not correct about photochemical smog is **Option 2**.

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