Should bulk cloudwater or fogwater samples obey Henry's law?

Abstract

In this work we prove that mixing of droplets with different pH that are individually in Henry's law equilibrium with the surrounding atmosphere always results in a bulk mixture that is supersaturated with weak acids like S(IV) and HCOOH and bases like NH3 with respect to the original atmosphere. The degree of supersaturation of the bulk liquid water sample for a particular species depends on its dissociation constant, on the initial pH of the bulk droplet mixture, and on the distribution of the pH and of the liquid water over the droplet spectrum. The theory developed can explain observed discrepancies from Henry's law in atmospheric samples and also other observed phenomena like the reported increase of pH values of bulk aqueous samples during storage. -from Authors