a) Ant two
| Physisorption |
Chemisorption |
| 1) It is arises because of vander waals force. |
1) It is caused by chemical bond formation. |
| 2) It is not specic in nature. |
2) It is highly specic in nature |
| 3) It is reversible in nature. |
3) It is irreversible. |
| 4) More easily liqueable gases are adsorbed readily. |
4) Gases which can react with the adsorbent show chemisorption. |
| 5) Enthalpy of adsorption is low (20-40 kJ mol-1) in this case. |
5) Enthalpy of adsorption is high (80-240 kJ mol-1) in this case. |
| 6) Low temperature is favourable for adsor ption. It decreases with increase of temperature. |
6) Hig temperature is favourable for adsorption. It increases with the increase of temperature. |
| 7) No appreciable activation energy is needed. |
7) High activation energy is sometimes needed. |
| 8) It increases with an increase of surface area. |
8) It too increases with an increase of surface area. |
b) Production of high vacuum, gas masks, control of humidity, removal of colouring matter from solutions, heterogeneous catalysis, separation of inert gases, in curing diseases, Froth oatation process, adsorption indicators, chromatographic analysis etc.
