Question

Compare physical adsorption and chemical adsorption in terms of rate and prevailing temperature.

Answer 1

Points	Physical adsorption (Physisorption)	Chemical adsorption (Chemisorption)
Rate of adsorption	The rate of physical adsorption is rapid because the energy of activation is almost zero, so adsorption proceeds quickly even at very low temperatures.	The rate of chemical adsorption may be rapid or slow depending on the system; it involves a high activation energy barrier, so the rate is slow at low temperatures and increases as temperature rises.
Prevailing temperature	Physical adsorption is favored at low temperatures. This is because the weak van der Waals forces involved strengthen below the critical temperature, and increasing temperature decreases adsorption.	Chemical adsorption occurs at relatively higher temperatures because the process requires sufficient energy to overcome the activation energy; adsorption extent first increases with temperature and then decreases due to its exothermic nature.