Given below are two statements:
Statement I : Pure Aniline and other arylamines are usually colourless.
Statement II : Arylamines get coloured on storage due to atmospheric reduction.
In the light of the above statements, choose the most appropriate answer from the options given below :

Solution

Chemistry ma’am · 4 steps

Fresh aniline is colourless; it browns on storage because air oxidises it, not because anything reduces it.

1. Statement I. Freshly distilled aniline and other pure arylamines are colourless liquids or solids. So Statement I is correct.
2. Why colour appears. The -NH₂ group pushes electron density into the benzene ring, which makes the ring electron rich and easy to oxidise. On storage, oxygen in the air slowly oxidises the arylamine to coloured products, so the sample turns yellow, then brown.
3. Statement II. The colour comes from atmospheric oxidation. Air does not reduce arylamines, so Statement II is incorrect.
4. So. Statement I is correct and Statement II is incorrect, which is option (b).

The idea to keep. Electron-rich compounds such as aniline and phenol darken on storage because air oxidises them. When a statement blames air for a reduction, check it again.

Answer from the NTA final answer key. Solution by PrepWiser.