Question

Freundlich adsorption theorem is valid for chemispotion.
A. True
B. False

Answer 1

The curve that expresses any variation in the amount of gas absorbed by the absorbent with pressure at constant pressure is known as Adsorption Isotherm . The adsorption isotherm which gives an empirical relationship between the amount of which is gas adsorbed by a unit mass of the solid adsorbent and pressure at a particular temperature is called the Freundlich Adsorption Isotherm.

Complete step by step solution:

Freundlich adsorption isotherm, also known as Freundlich equation, shows an empirical relation between the concentrations of a solute on the surface of an adsorbent to the concentration of the solute in the liquid with which it is in contact.
The Freundlich equation or Freundlich adsorption isotherm is mathematically expressed as
$\dfrac{x}{m}=K{{p}^{\dfrac{1}{n}}}$
The other forms of this expression are
$\log \dfrac{x}{m}=\log K+\dfrac{1}{n}\log p$
Where x=mass of the adsorbate and m=mass of the adsorbent.
P=Equilibrium pressure of adsorbate.
$\dfrac{x}{m}=K{{c}^{\dfrac{1}{n}}}$
$\log \dfrac{x}{m}=\log K+\dfrac{1}{n}\log c$
C= Equilibrium concentration of adsorbate in solution.
K and n are constants for a given adsorbate and adsorbent at a given temperature. At high pressure $\dfrac{1}{n}=0$, so the extent of adsorption becomes independent of pressure.
- Chemisorption is an adsorption which involves chemical reaction between surface and the adsorbent. In contrast with chemisorption is physisorption. Langmuir & BET adsorption isotherm is for physisorption. Langmuir Adsorption is related to monolayer adsorption while Fruendlich adsorption is related to multilayer adsorption.
- Thus we can see that this isotherm is valid for chemisorptions. The above given statement is true.

Note: Freundlich adsorption isotherm is based on chemisorptions. While Langmuir adsorption isotherm is based on physisorption.