Question

Adsorption is _________.
1. exothermic process
2. endothermic process
3. species dependent
4. no heat change

Answer 1

During adsorption, there is a decrease in the residual attractive forces present on the surface of the adsorbent, leading to decrease in the surface energy of the adsorbent, which is evolved as heat. Thus, the enthalpy of adsorption is negative and thereby, adsorption is essentially an exothermic process.