The reagent (s) used for the conversion of benzene diazonium hydrogen sulphate to benzene is/are

Options

A. `H_(2)O`
B. `H_(3)PO_(2) + H_(2)O`
C. `H_(2)SO_(4) + H_(2)O`
D. `CuCl//HCl`

Explanation

To convert benzene diazonium hydrogen sulfate to benzene, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Starting Compound**:
The starting compound is benzene diazonium hydrogen sulfate, which can be represented as C6H5N2^+HSO4^-.

2. **Determine the Reaction Conditions**:
The conversion of benzene diazonium salt to benzene requires specific reagents. The key reagent for this conversion is phosphorous acid (H3PO2).

3. **Write the Reaction**:
The reaction can be represented as follows:
\[ C6H5N2^+HSO4^- + H3PO2 \rightarrow C6H6 + N2(g) + HSO4^- \]
In this reaction, the diazonium group (N2^+) is replaced by a hydrogen atom, resulting in the formation of benzene (C6H6) and nitrogen gas (N2).

4. **Include Water in the Reaction**:
Water is also present in the reaction medium, which helps facilitate the conversion. Thus, the complete reaction can be summarized as:
\[ C6H5N2^+HSO4^- + H3PO2 + H2O \rightarrow C6H6 + N2(g) + HSO4^- \]

5. **Conclusion**:
The reagents used for the conversion of benzene diazonium hydrogen sulfate to benzene are phosphorous acid (H3PO2) and water.

### Final Answer:
The reagents used for the conversion of benzene diazonium hydrogen sulfate to benzene are H3PO2 (phosphorous acid) and water.

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