Aquatic chemistry of acid deposition

This article concentrates on three elementary chemical concepts that are the prerequisites to understanding the genesis and properties of acid deposition. First of the three concepts is a simple stoichiometric model, which explains on a mass balance basis that the composition of the rain results primarily from a titration of the acids formed from atmospheric pollutants with the bases introduced into the atmosphere. Next is an illustration of the absorption equilibria of such gases as SO//2 and NH//3 into water, which represents their interaction with cloud water, raindrops, fog droplets, or surface waters. Finally, a quantitative interpretation of the acid-base balance is presented.