JEE Main · 2019 · 10 Apr 2019 · Shift 1 · Practical and Analytical Chemistry

The principle of column chromatography is

(A)Differential absorption of the substances on the solid phase.
(B)Differential adsorption of the substances on the solid phase.✓ Correct
(C)Gravitational force.
(D)Capillary action.

Answer: (B)

Solution

Column chromatography separates a mixture by differential adsorption. The components have different affinities for the solid stationary phase, such as silica or alumina, so as the solvent carries the mixture down the column the strongly held components lag while the weakly held ones move ahead. The governing process is adsorption, a surface phenomenon, not bulk absorption.

JEE Main · 2019 · 10 Apr 2019 · Shift 1 · Single correct option

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