Question: 60. Which one of the following reactions does NOT give benzene as the product?
Answer: Option (4)
Explanation:
In reaction (1), sodium benzoate on heating with sodalime undergoes decarboxylation to give benzene. Thus this reaction produces benzene.
In reaction (2), n-hexane in the presence of at high temperature and pressure undergoes dehydrogenation and cyclization (aromatization) to form benzene.
In reaction (3), ethyne (acetylene), HC≡CH, when passed through a red hot iron tube at high temperature, undergoes trimerization to give benzene.
In reaction (4), benzene diazonium chloride on warming with water undergoes hydrolysis to form phenol, with evolution of nitrogen gas and formation of HCl, not benzene.
Therefore, the reaction that does NOT give benzene as the product is reaction (4).