Question

Does adsorption increase with temperature?

Answer 1

1. Adsorption - Adsorption is the phenomenon of attachment of the particles of a chemical substance to the surface of another chemical substance. It is of two types- Physisorption (adsorption through van der Waal bonds) and chemisorption (adsorption through a chemical reaction between an adsorbed substance and adsorbing substance). Molecules of adsorbed substances are known as adsorbate. Molecules of adsorbing substances are known as adsorbents.
2. Adsorption is an exothermic process. According to the Le-chatelier's principle on increasing temperature, exothermic reactions go in backward direction.
3. Physisorption decreases with an increase in temperature. This is because on increasing temperature already adsorbed particles get removed as the weak van der Waal bonds between them break apart which is in accordance with the exothermic nature of adsorption.
4. Chemisorption increases with an increase in temperature at first as the requirement of the activation energy for the reaction is fulfilled by an increase in temperature. Then it decreases due to the exothermic nature of adsorption.

So, physisorption decreases with an increase in temperature and chemisorption initially increases and afterwards decreases.