Question

If the solubility of a gas in water is 5.0 g/L when the pressure of the gas above the water is 2.5 atm, what is the pressure of the gas above the water when the solubility of the gas is 1.0 g/L?

Answer 1

Answer:

0.5 atm.

Explanation:

• Henry’s law states that the amount of a gas dissolved in a  solution is directly proportional to the  pressure of the gas above the solution

• We should use Henry’s law: P = KC,

where, P is the partial pressure of the  gaseous solute above the solution.

k is a constant.

C is the concentration of the  dissolved gas.

At two different pressures:

P₁C₂ = P₂C₁,

P₁ = 2.5 atm, C₁ = 5.0 g/L.

P₂ = ??? atm, C₂ = 1.0 g/L.

∴ P₂ = P₁C₂/C₁ = (2.5 atm)(1.0 g/L)/(5.0 g/L) = 0.5 atm.