The solubility of a gas depends on nature of gas, Nature of solvent, Temprature and pressure. The effect of equlibrium pressure of a gas on its solubility is studied by henry.
At a particular temperature, the solubility of a gas in a particular solvent is directly proportional to the equilibrium pressure present above the surface of solvent
I.e M direct proposnal to P
M = KhP ………………………eq 1
where M= solublity of gas
P = equilibrium pressure
Kh= Henry constant
Henry`s law can also be expressed in the forms of the Distribution Law.
For gas at equilibrium with liquid the ratio of concentration of gas in gaseous phase to concentration of gas in liquid phase remains constant at a particular temperature.
Limitation of Henry`s Law
It is applicable only if the following condition are satisfied.
1. the pressure should be low and temprature should be high I.e the gas behave like ideal gas.
2. The dissolved gas nither react with solvent not dissociate or associate with the solvent.