Use Henry’s law concept

Henry’s law can be written as $p = K_H x$ where:

• $p$ = partial pressure of gas,
• $x$ = mole fraction of gas dissolved in water,
• $K_H$ = Henry’s law constant.

Relation between solubility and $K_H$

For a given pressure, $x = \frac{p}{K_H}$ So, larger $K_H$ means smaller solubility.

Effect of temperature on gas solubility in water

Dissolution of most gases in water is exothermic. Therefore, when temperature increases, gas solubility decreases.

Since solubility decreases with temperature, and $x \propto \frac{1}{K_H},$ it follows that $K_H$ increases with temperature.

Shape of the graph

Therefore, the correct plot of $K_H$ versus temperature must show an increasing trend with temperature.

Choose the correct option

Hence, the correct graph is the one in which $K_H$ increases as temperature increases.

Therefore, Option B is correct.

Comparison with stored answer

Stored correct answer = B

Derived answer = B

So they agree.