Question

What is the effect of pressure on solubility of gases? Explain with examples.

Answer 1

Hint: The effect of pressure on the solubility of the gases is related with the gas law known as Henry’s gas law. The Henry’s law of gases is only applicable to ideal gas which gives the relation between the partial pressure and the concentration.

Complete step by step answer:
The effect of pressure on the solubility of gases is dependent on Henry's law. Henry's law states that the amount of gas which is dissolved in the liquid is directly related with the partial pressure of the gas at constant temperature. The proportionality constant used in this relation is known as Henry’s law of constant. The Henry’s law of constant is denoted by ${K_H}$
The Henry’s law constant is given by the formula as shown below.
\[P\propto C\]
$P = {K_H}C$
Where,
$P$ is the partial pressure of gas present in the atmosphere whose value is above liquid.
$C$ is the concentration of the gas dissolved in the solution.
${K_H}$ is the proportionality constant of Henry’s law.
From the Henry law of gases it is clear that the solubility of the gases is dependent on the partial pressure of the gas present above the liquid. As the partial pressure increases above the liquid, the solubility of the gases in the solution increases and when the partial pressure of the gas above liquid decreases the solubility of the gas in the solution decreases.

Note: The partial pressure is defined as the pressure exerted by all the gas molecules on the liquid. Dalton has also given a law on partial pressure known as Dalton law of partial pressure which says that the total pressure of the gas is equal to the addition of the partial pressure of the gases.