Abstract
At present there are two types of equilibrium constants in use for chemical reactions in concentrated multi-electrolyte solutions of geochemical and biochemical interest such as seawater, brines, and body fluids; thermodynamic and apparent (quasi-stoichiometric) constants. It will be shown that, in general, there is not enough information available for the application of thermodynamic constants to such media, because of ion association and pH changes, and that apparent constants should be used at present.
