Photo-Chemical Reduction of Water by Europium ( II ) Ion, and the Magnetic Susceptibilities of Europium ( II ) and ( III ) Ions

The slow reaction of europium (II) ion with hydrogen ion or to produce hydrogen and europium (III) ion has been reported. Prior to an investigation of the aqueous chemistry of europium (II) ion, the study of this reaction was undertaken. It was decided to follow the course of the reaction by observing the change in magnetic susceptibility of the reaction mixture, using a Gouy balance. This method was suggested by the aforementioned work of R. A. Cooley. Preliminary experiments showed that solutions 0.25 min europium (II) chloride and about 0.3 m in hydrochloric acid were stable over periods of weeks when kept in the dark, but evolved hydrogen and changed susceptibility rapidly when exposed to bright light (either sunlight or a tungsten lamp). One other such system has been reported in the literature. Poterill, Walker, and Weiss investigated the photo-chemical reduction of water by iron (II) ion.