JEE Main 2022ChemistrySurface ChemistryEasyMCQ

JEE Main 2022Surface Chemistry Question with Solution

JEE Main 2022 (29 Jul Shift 2)

Question

Given below are the critical temperatures of some of the gases:

Gas Critical temperature K
He 5.2
CH4 190
CO2 304.2
NH3 405.5

The gas showing least adsorption on a definite amount of charcoal is

Choose an option

Show full solutionCorrect option: A
Correct answer
AHe

Step-by-step explanation

The amount of gas adsorbed by a solid depends on the nature of gas. In general, easily liquefiable gases (i.e., with higher critical temperatures) are readily adsorbed as van der Waals’ forces are stronger near the critical temperatures. Thus, 1g of activated charcoal adsorbs more sulphur dioxide (critical temperature 630K), than methane (critical temperature 190K) which is still more than 4.5 mL of dihydrogen (critical temperature 33K).

So, more the critical temperature of gas greater is the ease of liquefaction hence greater is the adsorption.

Hence, among the given gases ammonia is adsorbed most and helium the least on definite amount of charcoal.

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About this question

This is a previous-year question from JEE Main 2022, covering the Surface Chemistry chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.