Molar solubility of CO2 in water is Concentration of CO2 = Henry\'s law constant x partial pressure of CO2 = (3.1x1^-2 mol / L.atm)(1.0atm) = 3.1x1^-2 mol / L Thus, the concentration of CO2 in water is 3.1x1^-2 mol / L. Solution Molar solubility of CO2 in water is Concentration of CO2 = Henry\'s law constant x partial pressure of CO2 = (3.1x1^-2 mol / L.atm)(1.0atm) = 3.1x1^-2 mol / L Thus, the concentration of CO2 in water is 3.1x1^-2 mol / L..