Question

Observe the following reaction \[ \mathrm{C_6H_5N_2Cl} \xrightarrow[\text{cold}]{X} Y \] \(Y\) reacts with aqueous NaOH solution and forms its sodium salt. What are \(X\) and \(Y\)?

• A. \(\mathrm{C_2H_5OH}\); Phenol
• B. \(\mathrm{C_2H_5OH}\); \(p\)-Cresol
• C. \(\mathrm{H_2O}\); \(p\)-Cresol
• D. \(\mathrm{H_2O}\); Phenol \bigskip

Hint:

Benzenediazonium chloride:

• With water \(\rightarrow\) Phenol.
• With KI \(\rightarrow\) Iodobenzene.
• With CuCl/HCl \(\rightarrow\) Chlorobenzene.
• With CuBr/HBr \(\rightarrow\) Bromobenzene.

Answer 1

The Correct Option is D

Step 1: Identify reagent \(X\). Benzenediazonium chloride undergoes hydrolysis on warming with water: \(\mathrm{C_6H_5N_2^+Cl^-} + \mathrm{H_2O} \rightarrow \mathrm{C_6H_5OH} + \mathrm{N_2} + \mathrm{HCl}\). Thus, \(X = \mathrm{H_2O}\).

Step 2: Identify product \(Y\). The product formed is phenol. Phenol reacts with aqueous NaOH to form sodium phenoxide: \(\mathrm{C_6H_5OH} + \mathrm{NaOH} \rightarrow \mathrm{C_6H_5ONa} + \mathrm{H_2O}\). Hence, \(Y = \mathrm{Phenol}\).

Step 3: Final conclusion. Therefore, \(\boxed{X=\mathrm{H_2O},\qquad Y=\mathrm{Phenol}}\)