Thermodynamic Model for Amorphous Pd(OH)2 Solubility in the Aqueous Na+-K+-H+-OH--Cl--ClO4--H2O System at 25 °C: A Critical Review

Only a limited number of experimental investigations have been conducted to determine hydrolysis constants of Pd(II) or the solubility product of Pd(II) hydroxide, and the reported values differ considerably from each other. No comprehensive reliable thermodynamic model is available for the Pd-OH and Pd-Cl systems. To obtain such a model, thermodynamic data for palladium compounds and complexes with chloride and hydroxide were critically evaluated using the SIT model. These evaluations, in most cases, involved reinterpretation of the original data reported in various publications to produce values of equilibrium constants for various reactions that are consistent with all of available reliable literature data. Final recommended values for solubility products and complexes of Pd(II) with hydroxide and chloride, along with the values for SIT ion interaction parameters, are tabulated.