Question

Why the solubility of gas in liquid decreases with increase in KH value at given pressure

Answer 1

Henry's Law states that:
Pgas=KhxPgas=Khx
⇒Kh=Pgasx⇒Kh=Pgasx
Here, xxis the mole fraction of the gas dissolved in the solvent, and PgasPgashappens to be the partial pressure of the gas over the solution.
Now let us assume that the entire system is open, say, we've kept the solution of gas in liquid in an open container, effectively ensuring that PgasPgasis a constant. Let's vary the temperature. As you can see in the above relation, KhKhmust vary inversely with mole fraction to keep the partial pressure constant.
Hence, we conclude that the Henry's Law constant varies inversely with mole fraction, which is a measure of solubility. Clearly, the value of KhKhrises with an increase in temperature, and vice-versa.