Which statement is/are correct?
i) Physical adsorption is due to Vander Waal's forces
ii) Physical adsorption decreases at high temperature
iii) Physical adsorption is irreversible
iv) Enthalpy for a chemical adsorption is generally lesser than that of physical adsorption
i, ii
Physical adsorption is reversible in nature.It takes place by the help of non-covalent attraction between adsorbate and adsorbent making the process reversible. & enthalpy for chemical adsorption is higher than that of physical adsorption