Question

The correct option(s) related to adsorption processes is(are)

• A. Chemisorption results in a unimolecular layer.
• B. Chemisorption is an endothermic process.
• C. Lowering the temperature favors physisorption processes.
• D. The enthalpy change during physisorption is in the range of $100$ to $140\text{kJ}{\text{mol}}^{-1}$.

Answer 1

Answer: (A), (C)

Lowering the temperature favors physisorption processes.

(A) Chemisorption is specific in nature so it involves formation of unimolecular layer only.
(B) In Physisorption $20-40\text{kJ}$ of heat is released.
(C) Heat is released in chemisorption so it is an exothermic process.
(D) Low temperature is favourable
for physisorption so it generally increases with decrease in temperature.