Platinum Oxysulphide, PtOS

Platinum Oxysulphide, PtOS.xН₂O, is obtained by allowing the disulphide in the wet condition to oxidise by exposure to air at about 70° to 100° C. with frequent stirring. The product is washed free from sulphuric acid, and dried at 100° C., when it results as a black powder. It is a powerful oxidiser, effecting the oxidation of hydrogen, hydrogen sulphide and of sulphur dioxide in the cold. Ferrous salts are oxidised by it, on warming, to the ferric condition, and oxalic acid to carbon dioxide.