Question

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:

• A. Both Statement-I and Statement-II are correct.
• B. Both Statement-I and Statement-II are incorrect.
• C. Statement-I is correct but Statement-II is incorrect.
• D. Statement-I is incorrect but Statement-II is correct.

Answer 1

The Correct Option is C

To determine the correct answer, we need to analyze each statement individually and understand the relevant chemical properties of aniline and arylamines.

1. Statement-I: Pure Aniline and other arylamines are usually colourless.
   • Aryl amines, such as aniline, are typically colorless when they are pure. This is a well-documented fact in organic chemistry, as their chemical structure doesn't inherently confer color. Hence, Statement-I is correct.
2. Statement-II: Arylamines get coloured on storage due to atmospheric reduction.
   • Aniline and other arylamines can indeed get colored upon exposure to air, but not due to "atmospheric reduction". They undergo oxidation when exposed to air, which is the opposite of reduction. This oxidation process can lead to the formation of colored impurities.
   • Oxidation results in the formation of compounds like quinone imines, which give a color to the originally colorless amines.
   • Hence, Statement-II is incorrect because it incorrectly identifies the process as reduction instead of oxidation.

Therefore, the correct choice is: Statement-I is correct but Statement-II is incorrect.