JEE Advanced levelSingle correct optionDifficulty 3 of 3sc038
Assertion (A): The Freundlich isotherm cannot describe adsorption at very high pressure of a gas.
Reason (R): The Freundlich equation predicts that the amount adsorbed keeps increasing with pressure, whereas a real surface becomes saturated.
Choose the correct option.
ABoth A and R are true and R is the correct explanation of A
BBoth A and R are true but R is not the correct explanation of A
CA is true but R is false
DA is false but R is true
Answer: A
Freundlich gives x/m=kp1/n, which rises indefinitely for 1/n>0. Real adsorption saturates at monolayer coverage (as in the Langmuir model), so the Freundlich equation fails at high pressure and R explains A.