Exercise 2 Question 5
What is an adsorption isotherm? Describe Freundlich adsorption isotherm.
The plot between the extent of adsorption (x/m) against the pressure of gas (P) at constant temperature (T) is called the adsorption isotherm.
Freundlich adsorption isotherm:
Freundlich adsorption isotherm gives an empirical relationship between the quantity of gas adsorbed by the unit mass of solid adsorbent and pressure at a specific temperature.
From the given plot it is clear that at pressure PS,(x/m) reaches the maximum valve. Ps is called the saturation pressure. Three cases arise from the graph now.
On plotting the graph between log (x/m) and log P, a straight line is obtained with the slope equal to (1 / n) and the intercept equal to log k.
