Identify the product of the following reaction.

The correct answer is Option (3) →

Core Concept:

Catalytic hydrogenation using H₂/Pd reduces the nitro group (–NO₂) to an amine group (–NH₂).

Explanation:

The given compound is nitrobenzene. When treated with hydrogen gas in the presence of palladium catalyst (H₂/Pd) in ethanol, the nitro group undergoes reduction. Catalytic hydrogenation selectively converts the –NO₂ group into –NH₂ without affecting the benzene ring. Thus, nitrobenzene is reduced to aniline.

Option 1: Nitrobenzaldehyde

Incorrect because hydrogenation does not introduce an aldehyde group; instead, it reduces the nitro group.

Option 2: Nitrobenzoic acid

Incorrect because the reaction does not oxidise or convert the nitro group into a carboxylic acid.

Option 3: Aniline

Correct because catalytic hydrogenation converts the nitro group to an amine group.

Option 4: Toluene

Incorrect because reduction does not replace the nitro group with a methyl group.