The Gaseous Oxides of the Platinum Metals

This paper reviews the experimental techniques used in the elucidation of the thermodynamics of the volatile oxides of the platinum metals in the temperature range 1200 to 1800°C. It is shown how the molecular formulae of the gases were obtained, and free energy equations of the two- term type are given for PtO₂, RhO₂, IrO₃, RuO₃ and OsO₃. At other temperatures oxides of different compositions may predominate, and approximate methods for calculating the thermodynamics of these from the present data are given.