ABSTRACT
The solubility of metal oxides in aqueous media is largely determined by the hydrolytic behavior of the dissolved metal ions. Even in pure binary systems, with MOn and H2O as the only components, many different species may exist in solution. The uncharged species M(OH)2n(aq), formed in the pH-independent equilibrium are seldom very stable and their concentration in saturated solutions is normally low. Solubility may be appreciably enhanced by the increase of temperature. Solubilities at high temperatures are important in several contexts: in geochemical hydrothermal media, in the development of preparative procedures for inorganic materials, and in the realm of corrosion science. Redox dissolution of mixed oxides is a matter of great practical importance. An important case arises when dissolution of mixed-metal oxides is required and the redox and hydrolytic properties of the two metals are very different.
