Question

A particular adsorption process has the following characteristics: (i) It arises due to van der Waals force and (ii) it is reversible.
Identify the correct statement that describes the above adsorption process.

• A. Adsorption is monolayer
• B. Energy of activation is low
• C. Adsorption increases with increases in temperature
• D. Enthalpy of adsorption is greater than $100{\text{kJ mol}}^{-1}$

Answer 1

The correct option is B Energy of activation is low

Physical adsorption process (physisorption) has the following characteristics.
(i) It arise to van der Waals force and (ii) its is reversible. The correct statement that describes the above adsorption process is option B. Energy of activation of physisorption is low.
(iii) Physisorption is multilayer. It decreases with increase in temperature and the enthalpy of physisorption is low (20- 40 kJ/mol).