Question

What are the factors which influence the adsorption of a gas on a solid?

Describe the factors which affect the adsorption of gases on solids.

Answer 1

There are various factors that affect the rate of adsorption of a gas on a solid surface.

1. Nature of the gas: Easily liquefiable gases such as NH₃, HCl, etc., are adsorbed to a great extent in comparison to gases such as H₂, O₂, etc. This is because Van der Waal’s forces are stronger in easily liquefiable gases.
2. Surface area of the solid: The greater the surface area of the adsorbent, the greater is the adsorption of a gas on the solid surface.
3. Effect of pressure: Adsorption is a reversible process and is accompanied by a decrease in pressure. Therefore, adsorption increases with an increase in pressure.
4. Effect of temperature: Adsorption is an exothermic process. Thus, in accordance with Le-Chatelier’s principle, the magnitude of adsorption decreases with an increase in temperature.