Heterogeneous equilibrium. CO2 dissolves in water to give "carbonic acid" (which is mostly dissolved CO2, as described in Box 6-4).
CO2(g) ⇌ CO2(aq) K = 10-1.5
(The equilibrium constant is called the Henry's law constant for carbon dioxide, because Henry's law states that the solubility of a gas in a liquid is proportional to the pressure of the gas.) The acid dissociation constants listed for "carbonic acid" in Appendix G apply to CO2(aq). Given that in the atmosphere is 10 -3.4 atm, find the pH of water in equilibrium with the atmosphere.