Freundlich isotherm is related with the pressure of gas adsorbed, as follows
x
m
=k.p1∕n where,
x
m
= amount of gas (x) adsorbed over the surface of mass (m). pressure of gas k = freundlich constant Thus, value of ' n ' is always greater than 1 and therefore value of 1∕n lies between 0 and 1 .