Which one of the following reactions does NOT give benzene as the product? (1) Sodium benzoate (C6H5COONa) with sodalime, δ; (2)…

Question

Which one of the following reactions does NOT give benzene as the product? (1) Sodium benzoate (C6H5COONa) with sodalime, δ; (2) n-hexane over Mo2O3 at 773 K, 10-20 atm; (3) ethyne (HCCH) through a red-hot iron tube at 873 K; (4) benzene diazonium chloride (C6H5N2^+Cl^-) with H2O, warm.

1. A. Sodium benzoate + sodalime, δ
2. B. n-hexane, Mo2O3, 773 K, 10-20 atm
3. C. HCCH, red-hot iron tube, 873 K
4. D. Benzene diazonium chloride + H2O, warm (Correct answer)

Correct Answer

Option D — Benzene diazonium chloride + H2O, warm

Detailed Solution & Explanation

The correct answer is benzene diazonium chloride + H$_2$O (warm).

Key Points

• Sodium benzoate + sodalime $\Delta$ (decarboxylation) $\to$ benzene.
• n-Hexane over Mo$_2$O$_3$ (aromatization) $\to$ benzene; ethyne through a red-hot iron tube (cyclic trimerization) $\to$ benzene.
• Benzene diazonium chloride warmed with water gives phenol (+ N$_2$ + HCl), not benzene — so this reaction is the exception.