Question

discuss the effect of temperature and pressure in adsorption of gases and what is freundlich adsorption isotherm??

Answer 1

Effect of pressure & temperature-

 

According to Le Chatelier’s principle, the magnitude of adsorption should increase with fall in temperature & since adsorption of a gas leads to decrease of pressure, the magnitude of adsorption increases with increase in pressure.If a equilibrium is subjected to a stress, the equilibrium shifts in such a way as to reduce the stress. Graphically , the variation of adsorption with pressure at given constant temperature is given by adsorption isotherm.


The relationship between magnitude of adsorption & pressure can be expressed mathematically by Freundlich Adsorption isotherm i.e  a = Kpn where a is the amount of gas adsorbed per unit mass of adsorbent at pressure p & K & n are constant depending upon the nature of gas & adsorbent.The value of n is less than 1 & therefore a does  not increase as rapidly as p.


The effect of temperature on the extent of adsorption at a given pressure of adsorbate is given by adsorption isobar.

Freundlich absorption isotherm:

The Freundlich equation or Freundlich adsorption isotherm, an adsorption isotherm, is an empirical relation between the concentration of a solute on the surface of an adsorbent to the concentration of the solute in the liquid with which it is in contact.


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Answer 2

According to Le Chatelier’s principle, the magnitude of adsorption should increase with fall in temperature & since adsorption of a gas leads to decrease of pressure, the magnitude of adsorption increases with increase in pressure.If a equilibrium is subjected to a stress, the equilibrium shifts in such a way as to reduce the stress. Graphically , the variation of adsorption with pressure at given constant temperature is given by adsorption isotherm.
The relationship between magnitude of adsorption & pressure can be expressed mathematically by Freundlich Adsorption isotherm i.e  a = Kpn where a is the amount of gas adsorbed per unit mass of adsorbent at pressure p & K & n are constant depending upon the nature of gas & adsorbent.The value of n is less than 1 & therefore a does  not increase as rapidly as p.
The effect of temperature on the extent of adsorption at a given pressure of adsorbate is given by adsorption isobar