If x is amount of adsorbate and m is amount of adsorbent, which of the following relations is not related to adsorption process?
- x/m = f(p) at constant T
- x/m = f(T) at constant p
- p = f(T) at constant (x/m)
- xm = p T
Answer
(4) xm = p T
Solution
Adsorption is described by three types of relations:
(i) Adsorption isotherm: x/m = f(p) at constant T, e.g. Freundlich isotherm xm = k p1/n
(ii) Adsorption isobar: x/m = f(T) at constant p
(iii) Adsorption isostere: p = f(T) at constant x/m
Physical adsorption decreases with rise in temperature, so x/m cannot be directly proportional to p T.
xm = p T is not related to adsorption.
Answer: (4)