can you please tell.. me what is the limitation of henry law?
Henry's Law only applies for sufficiently dilute solutions. The range of concentrations in which it applies becomes narrower the more the system diverges from ideal behavior.
It also only applies simply for solutions where the solvent does not react chemically with the gas being dissolved. A common example of a gas that does react with the solvent is carbon dioxide, which forms carbonic acid (H2CO3) to a certain degree with water.