About adsorption

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 Adsorption:


1- It is a surface phenomenon.

2- The concentration of the adsorbing substance (adsorbates) is higher at the surface (of adsorbent) than in the bulk.

3- It may be +ve or -ve depending on the larger or less concentrations of the adsorbed substance on the surface of the adsorbent.

* When the concentration of adsorbates is more on the surface of the adsorbent than in the bulk it is called positive adsorption, on the other hand, when the concentration of adsorbates is less on the surface of the adsorbent than in the bulk, it is called negative adsorption.

4- It is a rapid process.

5- The rate of adsorption is rapid initially but decrease slowly.

Examples: 

Water is adsorbed by silica gel.

Ammonia is absorbed by charcoal.

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