CHEMICAL ANALYSIS OF ALKALI METAL TUNGSTEN BRONZES

摘要: A method has been developed for the chemical analysis of three major constituents in alkali metal tungsten bronzes: metal, tungsten, and oxygen. The analyses are based on reactions bromine trifluoride hydrogen with bronzes. This analytical system successfully employed tungstates oxides as well Bromine reacts bronzes to produce tetrafluorobromate (III), hexafluoride, bromine, At temperature dry ice, oxygen is only product which not a solid; it transferred into constant volume manometer measurement. Subsequently, excess distilled out reactor. operation isolates tetrafluorobromate(III) easily rinsed reactor dilute sulfuric acid converted sulfate gravimetric determination. Because tungsten-- fluorine quite complex, necessary determine different manner. react oxide, water. Tungsten non-volatile remains reaction boat direct weighing. Although reduction valid formore » other compounds, cannot be used corresponding lithium compounds because low volatility oxide. Lithium dissolved by basic, oxidizing fusion converts bronze water-soluble tungstate. determined this case precipitation peroxide nitric acid; precipitate ignited weighed trioxide. capable determining all an accuracy better than 0.5 0.7 per cent relative values. Two interesting items information were produced research. One that oxygen-to-tungsten ratios orthotungstates really 4.000 3.000 respectively; appear anomalously oxygen-rich. determination correct conditions preparation trioxide so there no interferences changes stoichiometry. (auth)« less