Q. Which one of the following characteristics is not correct for physical adsorption?
A) Adsorption on solids is reversible
B) Adsorption increases with increase in temperature
C) Adsorption is spontaneous
D) Both enthalpy and entropy of adsorption are negative
Explanation
(b)
As temperature increases desorption increases.
Adsorbent +adsorbate$\ \rightleftharpoons \$Adsorbed state+$\mathrm{\Delta}E$
Adsorption is exothermic process (forward direction),
Desorption is endothermic process (backward direction).
According to Le-Chatelier’s principle increase in temperature favours endothermic process.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.