JEE Main levelSingle correct optionDifficulty 2 of 3sc018
Assertion (A): Physisorption of a gas on a solid decreases as temperature is raised at constant pressure.
Reason (R): Adsorption is an exothermic process.
Choose the correct option.
ABoth A and R are true but R is not the correct explanation of A
BA is true but R is false
CA is false but R is true
DBoth A and R are true and R is the correct explanation of A
Answer: D
Adsorption releases heat, so raising the temperature shifts the equilibrium towards desorption (Le Chatelier). Hence the decrease of physisorption with temperature is directly explained by the exothermic nature.