The adsorption depends upon the following character.
- Nature of the gas.
- Effect of temperature.
- Effect of pressure.
- Nature of the adsorbent.
Nature of the Gas:
It is depends on the nature of gas . Easily liquefiable gases are adsorbed readily. The reason is inter-molecular forces which are involved in adsorption. This is valid for physical adsorption only.
Since chemical adsorption is specific in nature, it occurs only if the gas can form a chemical bond with the solid.
Effect of temperature:
Adsorption is a exothermic process. Therefore in accordance with Le chartelier's principle, the magnitude of adsorption increases with decrease in temperature. It is in the case of physical adsorption.
Since chemical adsorption first increases with rise in the temperature and then stats decreases.
Effect of Pressure:
Physical adsorption is reversible nature. Since adsorption of a gas leads to decrease of pressure, the magnitude of adsorption increases with increase in pressure.
Nature of the adsorbent:
Adsorption is a surface phenomenon.Increase in the surface area of the adsorbent, increases the total amount of gas adsorbed.