Question

X is-

• A.
• B.
• C.
• D. None of these

Answer 1

Answer: (B)

B

Answer 2

The given reaction sequence involves two steps.

Step 1: Formation of X

The starting material, aniline (C₆H₅NH₂), reacts with sodium nitrite (NaNO₂) and hydrochloric acid (HCl) at a low temperature (273 K). This is diazotization, where an aromatic primary amine converts into an aromatic diazonium salt.

The reaction is:

$\text{C}_6\text{H}_5\text{NH}_2 + \text{NaNO}_2 + 2\text{HCl} \xrightarrow{273 \text{ K}} \text{C}_6\text{H}_5\text{N}_2^+\text{Cl}^- + \text{NaCl} + 2\text{H}_2\text{O}$

Compound X is benzenediazonium chloride.

Step 2: Reaction of X to form Iodobenzene

Compound X (benzenediazonium chloride) reacts with potassium iodide (KI) upon heating (Δ) to form iodobenzene (C₆H₅I).

$\text{C}_6\text{H}_5\text{N}_2^+\text{Cl}^- + \text{KI} \xrightarrow{\Delta} \text{C}_6\text{H}_5\text{I} + \text{N}_2 + \text{KCl}$

This confirms X is benzenediazonium chloride.