Physisorption
| Chemisorption
|
1.
| In this type of adsorption, the adsorbate is attached to the surface of the adsorbent with weak van der Waal’s forces of attraction.
| In this type of adsorption, strong chemical bonds are formed between the adsorbate and the surface of the adsorbent.
|
2.
| No new compound is formed in the process.
| New compounds are formed at the surface of the adsorbent.
|
3.
| It is generally found to be reversible in nature.
| It is usually irreversible in nature.
|
4.
| Enthalpy of adsorption is low as weak van der Waal’s forces of attraction are involved. The values lie in the range of 20-40 kJ mol-1.
| Enthalpy of adsorption is high as chemical bonds are formed. The values lie in the range of 40-400 kJ mol-1.
|
5.
| It is favoured by low temperature conditions.
| It is favoured by high temperature conditions.
|
6.
| It is an example of multi-layer adsorption
| It is an example of mono-layer adsorption.
|