Ruthenium redox equilibria: 2. Thermodynamic analysis of disproportionation and comproportionation conditions

Abstract

The key property of Frost diagram has been confirmed using thermodynamic and linear algebra methods. On the basis of the thermodynamic data, the areas of thermodynamic stability of ruthenium chemical species in different valence states as a function of pH for each degree of oxidation have been determined. Subsequently, based on the diagrams, calculated for several values of pH, a narrow ΔpH value is determined, in which the dismutation of appropriate form takes place. Based on thermodynamic analysis, the exact value of the beginning of disproportionation (or comproportionation) is found. Finally, the developed revised Frost diagrams of ruthenium heterogeneous chemical and redox equilibria, as a function of pH and the total concentration of metal ion in solution, have been built.