Below the water table, the groundwater aquifer is a closed system with respect to exchange of CO2 with a separate vapor phase. Without an external source or sink for dissolved CO2 in groundwater (i.e., no carbonate) the dissolved carbon concentration should be constant. Assuming that the ground water at the water table is in equilibrium with the atmosphere with CO2 at 10-3.5 atm partial pressure, construct a plot showing the change in CO2 with pH in the closed system.