JEE Main · 2024 · 06 Apr 2024 · Shift 2 · Practical and Analytical Chemistry

The correct statements among the following, for a "chromatography" purification method is:

(A)Organic compounds run faster than solvent in the thin layer chromatographic plate.
(B)Non-polar compounds are retained at top and polar compounds come down in column chromatography.
(C) $R_{f}$ of a polar compound is smaller than that of a non-polar compound.✓ Correct
(D) $R_{f}$ is an integral value.

Answer: (C)

Solution

In (normal-phase) chromatography, polar compounds interact more strongly with the polar stationary phase and travel more slowly, giving them a smaller

R_{f}

; non-polar compounds move faster and show a larger

R_{f}

. Hence

R_{f} (polar) < R_{f} (non-polar)

JEE Main · 2024 · 06 Apr 2024 · Shift 2 · Single correct option

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