Which of the following reagent does not give `O_2` gas on reaction with Ozone ?

Options

A. `KMnO_4`
B. `SnCl_2//HCl`
C. `FeSO_4//H_2SO_4`
D. PbS

Answer

To solve the question "Which of the following reagents does not give O₂ gas on reaction with Ozone?", we will analyze each reagent mentioned in the options and determine whether they produce oxygen gas when reacted with ozone.

### Step-by-Step Solution:

1. **Identify the Reagents**:
We need to analyze the following reagents:
- Lafore
- SnCl₂ (Tin(II) chloride)
- FeSO₄ (Iron(II) sulfate)
- PbS (Lead(II) sulfide)
- KMnO₄ (Potassium permanganate)

2. **Reagent Analysis**:
- **Lafore**: This reagent does not react with ozone, so it does not produce O₂ gas.
- **SnCl₂**: When SnCl₂ reacts with ozone in the presence of HCl, it reduces ozone, leading to the formation of SnCl₄ and water, but no O₂ gas is produced.
- **FeSO₄**: When FeSO₄ reacts with ozone, it produces Fe₂(SO₄)₃ and liberates O₂ gas.
- **PbS**: When PbS reacts with ozone, it produces PbSO₄ and liberates O₂ gas.
- **KMnO₄**: This reagent does not react with ozone, so it does not produce O₂ gas.

3. **Conclusion**:
From the analysis, we can conclude that the reagents that do not produce O₂ gas when reacted with ozone are **Lafore** and **SnCl₂**. However, since the question asks for a single reagent, we can conclude that **SnCl₂** is the most commonly referenced reagent that does not produce O₂ gas with ozone.

### Final Answer:
**SnCl₂ (Tin(II) chloride)** does not give O₂ gas on reaction with ozone.

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