Benzenediazonium chloride can be converted into benzene on treatment with:

Options

A. `H_(3)PO_(3)`
B. `H_(3)PO_(4)`
C. `H_(3)PO_(2)`
D. `HPO_(3)`

Answer

To convert benzenediazonium chloride into benzene, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Compound**:
The compound we are starting with is benzenediazonium chloride, which has the chemical formula C6H5N2Cl.

2. **Understand the Reaction**:
Benzenediazonium chloride can undergo a reduction reaction to form benzene (C6H6). In this process, the diazonium group (N2) is replaced by a hydrogen atom (H).

3. **Choose the Reducing Agent**:
To achieve this conversion, we need a suitable reducing agent. The common reducing agents for this type of reaction are sodium stannite (Na2SnO2) or hypophosphorous acid (H3PO2).

4. **Write the Reaction**:
The reaction can be represented as follows:
\[ C6H5N2Cl + H3PO2 \rightarrow C6H6 + N2 + HCl \]
Here, the diazonium group (N2) is released as nitrogen gas, and hydrochloric acid (HCl) is formed as a byproduct.

5. **Conclusion**:
Therefore, the correct treatment to convert benzenediazonium chloride into benzene is with hypophosphorous acid (H3PO2).

### Final Answer:
The correct option is **C: H3PO2**.

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