Which of the following characteristics is/are correct for physical adsorption?
Physisorption is also known as physical adsorption and it is an exothermic process. Its adsorption enthalpy is low, nearly 20 to 40 kJ/mol. Normally in physisorption, the gas is accumulated on the solid surface due to weak force, known as Van der Waals forces.
Physisorption lacks specificity because of the adsorbent (the surface or the material on which the process of adsorption takes place) in the given surface does not show any particular gas. It has reversible nature that is physisorption of gas by a solid can be reversed to a solid by gas.
As the temperature increases, the kinetic energy of adsorbate molecules increases and due to weak van der waals forces, adsorption will not take place. So physical adsorption takes place at low temperature.