Question

The end product $\left(Z\right)$ of the given reaction is:

• A. a cyanide
• B. a carboxylic acid
• C. an amine
• D. an arene

Answer 1

The correct option is D an arene

When benzene diazonium chloride is treated with CuCN, the diazonium group is replaced with CN group to obtain benzonitrile (compound X).
Benzonitrile of hydrolysis forms benzoic acid (compound Y).
When benzoic acid is heated with NaOH, CaO, it undergoes decarboxylation to form benzene (compound Z).
$\underset{\text{Benzene diazonium chloride}}{Ph-N=N-Cl}\stackrel{CuCN}{\to }\underset{\text{Benzonitrile, X}}{PhCN}\stackrel{H^{+}/H_{2}O}{\to }\underset{\text{Benzoic acid, Y}}{Ph-COOH}\underset{CaO,\Delta }{\overset{NaOH}{\to }}\underset{\text{Benzene, Z}}{Ph-H}$