Question

Which of the following reagents cannot be used for the conversion of nitrobenzene to aniline?

• A. $H_2/\mathrm{Pd}\mathrm{in}\mathrm{ethanol}$
• B. $\mathrm{Fe}+\mathrm{HCl}$
• C. $\mathrm{Zn}/{\mathrm{NH}}_4\mathrm{Cl}$
• D. ${\mathrm{HNO}}_3+H_2{\mathrm{SO}}_4$

Answer 1

Answer: (C), (D)

The correct options are
C $\mathrm{Zn}/{\mathrm{NH}}_4\mathrm{Cl}$
D ${\mathrm{HNO}}_3+H_2{\mathrm{SO}}_4$

Catalytic hydrogenation (passing hydrogen gas in the presence of finely divided nickel, palladium or platinum) of nitrobenzene gives aniline as the product. Nitrobenzene on treatment with metals (tin, iron etc.) in acidic medium also results in aniline.
Nitrobenzene, when treated with zinc in presence of ammonium chloride, gives N-phenylhydroxylamine.
Addition of HNO₃ and H₂SO₄ (nitrating mixture) to nitrobezene results in dinitrobenzene.