In this article we will discuss about the meaning of adsorption, with the help of suitable diagram.
Adsorption is a surface phenomenon when two phases are brought together into contact with each other, one phase or some constituent gets accumulated more at the interface than in bulk. This phenomenon of accumulation at interface is bonding between two phases is called adsorption.
Adsorption occurs on active site of solid surface. Active sites are homogeneous when they all contain same energy potential, with different energy potentials the sites are said to be heterogeneous. Principle of separation by adsorption is given in Figs. 10.1. 10.2. Fig.
If the bonds formed between adsorbate-adsorbent, are very weak, adsorption is called physical adsorption and involves vander wall forces. Heat of adsorption is 5 A: cal/mol. If the bond between absorbent and adsorbent, are very strong, the process is almost irreversible the phenomenon of adsoprtion is chemisorption, Heat of adsorption is 20-100 kcal/mol.