Adsorption is a process which involves the accumulation of a substance in molecular species in higher concentration on the surface. For the adsorption process, two components are required,
- Adsorbate: Substance that is deposited on the surface of another substance. For example, H2, N2 and O2 gases.
- Adsorbent: Surface of a substance on which adsorbate adsorbs. For example, Charcoal, Silica gel, Alumina.
The difference between physical and chemical adsorption are tabulated below.
|Physical adsorption||Chemical Adsorption|
|This type of adsorption is also known as physisorption.||This type of adsorption is also known as chemisorption.|
|It is due to weak Van der Waals forces between adsorbate and adsorbent.||It is due to strong chemical forces of bonding type between adsorbate and adsorbent.|
|This adsorption is a multi-layered process.||This type of adsorption is almost a single-layered phenomenon.|
|Surface area, temperature, pressure, nature of adsorbate effects physisorption||Surface area, temperature, nature of adsorbate effects chemisorption.|
|Examples: H2 and N2 gases adsorb on coconut charcoal||Examples: Charcoal, Silica gel, Alumina.|