question_answer

A particular adsorption process has the following characteristics:

(i) It arises due to vander Waals forces and

(ii) it is reversible. Identify the correct statement that describes the above adsorption process:

    JEE Main Online Paper (Held On 09 April 2016)

A) Enthalpy of adsorption is greater than \[100 \text{kJ}\,\text{mo}{{\text{l}}^{\text{-1}}}.\]

B) Adsorption is monolayer.

C) Adsorption increases with increase in temperature.

D) Energy of activation is low.

Correct Answer: D

Solution :

                Adsorption aries due to Vander waal forces & reversible, hence it should be physisorption (physical adsorption). (i) Enthalpy of physisorption is low (20 . 40 kJ/mol) (ii)In physisorption multimolecular layer form. (iii) Physisorption decreases with increase in temperature. (iv) Physisorption required number activation energy. Hence answer is (d)