Question

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

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

Answer 1

Answer: (A), (D)

Chemisorption results in a unimolecular layer.

Answer 2

(A) The initial assertion is accurate since chemisorption yields a monomolecular layer, while physisorption leads to a multimolecular layer.

(B) The subsequent claim is inaccurate because the enthalpy shift in physisorption typically falls within the range of (20 – 40) kJ mol–1.

(C) Chemisorption demonstrates an exothermic characteristic, with an enthalpy of adsorption ranging from (80 – 240) kJ mol–1.

(D) A reduction in temperature prompts an augmentation in the degree of physisorption.

Consequently, statements (A) and (D) are correct.