Question

What is the equilibrium concentration of carbon dioxide in water that is in contact with air at 25 °C and 4.53 atm. The mole fraction of CO2 in air is 3.01×10-4. The Henry's law constant for carbon dioxide is 4.48×10-5 M/mmHg.

Answer 1

mole fraction = 3.01 x 10^-4

total pressure = 4.53 atm

                      = 4.53 x 760 mmHg

                       = 3443 mm Hg

partial pressure = mole fraction x total pressure

                          = 3.01 x 10^-4 x 3443

                         = 1.036 mmHg

now concentration =   henry law constant x partial pressure

                               = 4.48×10-5 M/mmHg x 1.036 mmHg

                              = 4.64 x 10^-5 M

equilibrium concentration of carbon dioxide = 4.64 x 10^-5 M