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