Phosphorus pentachloride reacts with sulfur dioxide to form

Options

A. Chlorosulfonic acid
B. Phosphoric acid
C. Thionyl chloride
D. Sulfuryl chloride

Explanation

To solve the question regarding the reaction of phosphorus pentachloride (PCl5) with sulfur dioxide (SO2), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this reaction are phosphorus pentachloride (PCl5) and sulfur dioxide (SO2).

2. **Write the Chemical Reaction**:
- When PCl5 reacts with SO2, the general reaction can be represented as:
\[ \text{PCl}_5 + \text{SO}_2 \rightarrow \text{Products} \]

3. **Determine the Products**:
- From the reaction of PCl5 with SO2, we know that it produces thionyl chloride (SOCl2) and phosphoryl chloride (POCl3).
- Thus, the products can be written as:
\[ \text{PCl}_5 + \text{SO}_2 \rightarrow \text{SOCl}_2 + \text{POCl}_3 \]

4. **Identify the Correct Answer**:
- Among the options provided:
- Option 1: Chlorosulfonic acid
- Option 2: Phosphoric acid
- Option 3: Thionyl chloride
- Option 4: Sulfuryl chloride
- The correct product formed in this reaction is thionyl chloride (SOCl2), which corresponds to Option 3.

5. **Conclusion**:
- Therefore, the answer to the question is that phosphorus pentachloride reacts with sulfur dioxide to form thionyl chloride.

### Final Answer:
Phosphorus pentachloride reacts with sulfur dioxide to form thionyl chloride (SOCl2).

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