Question

Freundlich isotherm becomes independent of pressure at high pressure for a gas absorbed on a solid. Give reason. [Uttarakhand 2019]

Answer 1

Explanation:

Freundlich gave an empirical relationship between the quantity of gas adsorbed by a unit mass of solid adsorbent and pressure at a particular temperature

Answer 2

Answer:

At high pressure, Freundlich isotherm fails. Because the extent of absorption becomes constant.

Explanation:

According to Freundlich isotherm, the relationship of extent of absorption and pressure is given as:

                      $a=\frac{x}{m}=kP^{\frac{1}{n} }$

where x = mass of adsorbate

           m= mass of adsorbent

For high pressure, n =∞

           ∴                1/n = 0

           ∴                 $\frac{x}{m} =KP^{0}\\ \\ \frac{x}{m} =K$

Therefore, at high pressure Freundlich isotherm becomes independent of pressure.