Which reagent is used to get iodo benzene from benzene diazonium acid sulphate `[C_(6)H_(5)N_(2)HSO_(4)]`?

Options

A. `CuBr,Delta`
B. Cu power + HI
C. `KI,Delta`
D. None of these

Answer

To convert benzene diazonium acid sulfate \([C_{6}H_{5}N_{2}HSO_{4}]\) into iodobenzene, we can follow these steps:

### Step 1: Identify the Reaction
The conversion of benzene diazonium salts to aryl halides can be achieved by using the appropriate halide source. In this case, we want to form iodobenzene.

### Step 2: Choose the Reagent
To convert benzene diazonium acid sulfate to iodobenzene, we need to use potassium iodide (KI) as the reagent. This is because KI provides iodide ions (I⁻) necessary for the substitution reaction.

### Step 3: Conduct the Reaction
When benzene diazonium acid sulfate reacts with potassium iodide and is heated, the following reaction occurs:
\[ C_{6}H_{5}N_{2}HSO_{4} + KI \xrightarrow{heat} C_{6}H_{5}I + N_{2} + KHSO_{4} \]
In this reaction, the diazonium group (\(-N_{2}^{+}\)) is replaced by an iodine atom, resulting in the formation of iodobenzene \((C_{6}H_{5}I)\), nitrogen gas (\(N_{2}\)), and potassium hydrogen sulfate \((KHSO_{4})\).

### Step 4: Conclusion
Thus, the reagent used to convert benzene diazonium acid sulfate to iodobenzene is potassium iodide (KI).

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