Question

Which of the following is obtained on heating aqueous solution of benzene diazonium chloride?

• A. Benzene
• B. Benzyl alcohol
• C. Phenol
• D. Chlorobenzene

Hint:

Remember: Simple heating of diazonium salts with water gives phenols. With Cu salts, different substituted benzene derivatives are obtained.

Answer 1

The Correct Option is C

Step 1: Reaction principle.
Benzene diazonium chloride (C$_6$H$_5$N$_2$Cl) when heated with water undergoes hydrolysis to give phenol, nitrogen gas, and hydrochloric acid.
Step 2: Reaction.
\[ C_6H_5N_2Cl + H_2O \xrightarrow{\Delta} C_6H_5OH + N_2 + HCl \] Step 3: Analysis of options.
(A) Benzene: Not formed here.
(B) Benzyl alcohol: Incorrect product.
(C) Phenol: Correct, formed as the major product.
(D) Chlorobenzene: Obtained with CuCl (Sandmeyer’s reaction), not by hydrolysis.
Step 4: Conclusion.
Thus, the correct answer is (C) Phenol.