Q. Which of the following statements is incorrect regarding physisorptions?
A) It occurs because of van der Waals’ forces
B) More easily liquefiable gases are adsorbed readily
C) Under high pressure it results into multimolecular layer on adsorbent surface
D) Enthalpy of adsorption $(\mathrm{\Delta}H_{adsorption})$ is slow and positive
Explanation
(d)
Adsorption is an exothermic process i.e., energy is released against van der Waals’ force of attraction (physisorptions).
Hence, $\mathrm{\Delta}H$ is always negative.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.