With the increase in surface area of adsorbent, chemical adsorption increases. If the adsorbent surface is more fine or rough, the surface area will be greater; hence the adsorption will be greater.
Chemical and physical adsorption
Physical absorption occurs when the adsorbate gas molecules are held by physical forces like Van der Waals forces. Chemical adsorption occurs when the adsorbate molecule is held on the adsorbent surface by chemical forces as short covalent chemical bonding occurs by sharing electrons.
- Physical adsorption is more a function of the adsorbate.
- Physical adsorption is more pronounced at a temperature below the boiling point of the adsorbate.
- Chemical adsorption has a characteristic function of both adsorbate and adsorbent.
- Chemical Adsorption is more usually pronounced at a high temperature.