Which one of the following statements is false

Options

A. Photochemical smog causes irritation in eyes
B. London smog is a mixture of smoke and fog
C. Photochemical smog results in the formation of PAN
D. London smog is oxidizing in nature

Answer

To solve the question, we need to evaluate each of the statements provided and identify which one is false. Let's go through the options step by step.

### Step-by-Step Solution:

1. **Evaluate the First Statement:**
- **Statement:** Photochemical smog causes irritation in eyes.
- **Analysis:** Photochemical smog is known to contain various pollutants, including peroxyacetyl nitrate (PAN), which can irritate the eyes. Therefore, this statement is **true**.

2. **Evaluate the Second Statement:**
- **Statement:** London smog is a mixture of smoke and fog.
- **Analysis:** London smog, historically associated with the city of London, is indeed a mixture of smoke (from burning coal) and fog. Hence, this statement is also **true**.

3. **Evaluate the Third Statement:**
- **Statement:** Photochemical smog results in the formation of PAN.
- **Analysis:** Photochemical smog is characterized by the formation of PAN (peroxyacetyl nitrate) due to reactions involving sunlight and pollutants. Thus, this statement is **true**.

4. **Evaluate the Fourth Statement:**
- **Statement:** London smog is oxidizing in nature.
- **Analysis:** London smog is primarily composed of sulfur dioxide (SO2) and particulate matter, which are reducing agents. Therefore, the statement that London smog is oxidizing in nature is **false**.

### Conclusion:
The false statement among the options is the fourth one: "London smog is oxidizing in nature."

### Final Answer:
**Option D: London smog is oxidizing in nature.** (This statement is false.)

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