Thermodynamic Feasibility (or Spontaneity) of Adsorption Chemistry Notes

Thermodynamic Feasibility (or Spontaneity) of Adsorption :

The amount of heat released during the adsorption of one mole adsorbate at the surface of adsorbent in an adsorption phenomenon is called molar adsorption heat.
Adsorption is always an exothermic reaction and the value of ∆H is negative.
When a gas is adsorbed then the movement of molecules decreases and entropy of gas decreases. So, the value of ∆S is negative.
Gibbs Helmholtz equation ∆G = ∆H – T∆S. At normal temperature ∆H > T∆S, so the value of ∆G is negative, hence, adsorption is a spontaneous process.