Write three distinct features of chemisorptions which are not found in physisorptions.
Chemisorption is a kind of adsorption which involves a chemical reaction between the surface and the adsorbate.
Physisorption, also called physical adsorption, is a process in which the electronic structure of the atom or molecule is barely perturbed upon adsorption.
|
S. No. |
Point of difference |
Physiosorption |
Chemisorption |
|
(i) |
Specificity |
This is not specific in nature. |
This is highly specific in nature. |
|
(ii) |
Temperature dependence |
Low temperature is favourable for physiosorption. It decreases with increase in temperature. |
High temperature is favourable for chemisorption. It increases with the increase in temperature. |
|
(iii) |
Reversibility |
This is reversible in nature. |
This is irreversible in nature. |
|
(iv) |
Enthalpy change |
Enthalpy of adsorption is low. |
Enthalpy of adsorption is high. |
