Solubility of aluminum, gallium, and indium perchlorates in water

Solubility polytherms of the system M(ClO4)3-H2O (M3+ = Al3+, Ga3+, In3+) were measured. Positions of singular points and vitrification ranges were determined. Values of eutectic concentrations were compared with earlier known data on the inversion concentrations measured by the viscometry method. Compositions of found crystalline hydrates were calculated from the solubility polytherms. The concept of the ability of the studied aqua cations to show properties of aqua acids, of the structure of solutions of posteutectic concentrations (structurally forced processes and microheterogeneity), of the electronic structure of M3+ cations, and of the localized hydrolysis phenomenon were used to understand the existence of the polyaqua compounds.