Calculate the solubility of o2 in water at a partial pressure of o2 of 120 torr at 25 ̊c. the henry's law constant for o2 at 25 ̊c is 1.3 x 10-3 mol/l atm. how do you expect the solubility to change if the temperature were decreased?

1) 2.054 x 10⁻⁴ mol/L.

2) Decreasing the temperature will increase the solubilty of O₂ gas in water.

Explanation:

1) The solubility of O₂ gas in water:

We cam calculate the solubility of O₂ in water using Henry's law: Cgas = K P, where, Cgas is the solubility if gas, K is henry's law constant (K for O₂ at 25 ̊C is 1.3 x 10⁻³ mol/l atm), P is the partial pressure of O₂ (P = 120 torr / 760 = 0.158 atm). Cgas = K P = (1.3 x 10⁻³ mol/l atm) (0.158 atm) = 2.054 x 10⁻⁴ mol/L.

2) The effect of decreasing temperature on the solubility O₂ gas in water:

Decreasing the temperature will increase the solubilty of O₂ gas in water. When the temperature increases, the solubility of O₂ gas in water will decrease because the increase in T will increase the kinetic energy of gas particles and increase its motion that will break intermolecular bonds and escape from solution. Decreasing the temperature will increase the solubility of O₂ gas in water will because the kinetic energy of gas particles will decrease and limit its motion that can not break the intermolecular bonds and increase the solubility of O₂ gas.