Factors affecting adsorption of Gases by Solids
- Nature and Surface area of adsorbent:
- The same gas is adsorbed by different solids at different extents even at the same temperature.
- Greater the surface area, greater is the volume of gases adsorbed.
- Nature of the gas being adsorbed:
- Different gases are adsorbed are adsorbed to different extents even by the same solid.
- As the critical temperature of a gas increases, it is easier to liquefy and it is also more readily adsorbed.
- Reason- Higher the critical temperature, the easier it is to liquefy the gas as greater are the intermolecular forces to attraction between the molecules of the gas. For such a gas, the intermolecular forces of attraction are greater on the surface of the adsorbent and thus, the adsorption will be more.
- Temperature: As temperature increases, adsorption decreases
- Pressure: At constant temperature, the adsorption of a gas increases with increase in pressure.
- Activation of the solid adsorbent: It means increasing the adsorbing power of the adsorbent.
It can be done by-
- Making the surface of the adsorbent rough- It can be done by rubbing the surface or chemical action or by depositing fine metal particles on the surface by electroplating
- By dividing the adsorbent into small pieces or grains- It increases the surface area but this method has a practical limitation. If the particles are too fine like powder, the adsorption of the gas will become difficult.
- By removing the already adsorbed gases