RESEARCH ON CHARACTERISTICS OF TRANSITION ELEMENTS IN SOLUTION. 1. STUDIES ON RHODIUM CHEMISTRY, WITH A NOTE ON PALLADIUM. 2. STUDIES ON RUTHENIUM CHEMISTRY

Systematic studies were made on the preparation and characterization of halogenide-free rhodium sulfate and perchlorate solutions. Improved methods of preparation and analysis were worked out. Some redox emfs for RhIII, V mixtures are given. They do not correspond to real equilibrium, but the apparent standard electrode potential in 0.5 - 1 M HClO4 is around 1.42 V. Absorption spectra are given for the solution prepared. Pure palladiumII perchlorate and sulfate solutions were prepared by precipitating first - with HClO4 hydrous palladium oxide from a clear alkaline solution of PdNO32 and then dissolving the precipitate in cold HClO4 H2SO4. Redox reactions of Ru in 1 M H2SO4 medium were studied The oxidation number was varied step wise by chemical means TiIII, CrII, CeIV or coulometrically, and e was measured. The resulting curves bring out the existence of slow, irreversible reactions, and of polynuclear species of mixed oxidation number.