JEE Chemistry 2024 Question with Solution

Given: The chromatographic techniques listed are A. Column chromatography, B. Thin layer chromatography, and C. Paper chromatography.

Find: Which technique(s) are based on the principle of differential adsorption.

Differential adsorption means different components of a mixture are adsorbed to different extents on a stationary phase, so they move at different rates and get separated.

• Column chromatography uses a stationary adsorbent such as silica or alumina and separates substances on the basis of differential adsorption.
• Thin layer chromatography also uses an adsorbent stationary phase and works on the same principle of differential adsorption.
• Paper chromatography primarily works on the principle of partition, not differential adsorption.

Therefore, the techniques based on differential adsorption are A and B only.

The correct option is C.

Given: Chromatography separates components of a mixture based on their different affinities for the stationary and mobile phases.

Find: Which of the given techniques specifically use differential adsorption.

1. Understanding the principle

• In differential adsorption, different substances adhere to the stationary phase with different strengths.
• A component with stronger adsorption moves more slowly, while one with weaker adsorption moves faster.

2. Checking each technique

• Column chromatography (A): uses a packed adsorbent stationary phase such as silica or alumina, so separation occurs by differential adsorption.
• Thin layer chromatography (B): uses a thin adsorbent layer, usually silica gel, so separation also occurs by differential adsorption.
• Paper chromatography (C): mainly involves partition between the liquid phase held in paper and the mobile solvent, so it is not primarily adsorption-based.

3. Conclusion Only A and B satisfy the required principle.

Hence, the correct answer is A & B only, which corresponds to option C.