oa Loss of Platinum Oxide from Heated Platinum

The loss of weight of platinum heated in air is fortunately low, owing to the very low vapour pressure of the PtO2 that volatilises. This article reviews recent studies of heated platinum filaments which suggest that a viscous boundary layer of gas hinders escape of the PtO2 molecules that are formed. At atmospheric pressure 99.85 per cent of the molecules of PtO2 formed may be trapped in this layer.