非化学计量钨氧化物及钨青铜类化合物氧指数的精确测定

ACCURATE MEASUREMENT OF OXYGEN INDEX OF TUNGSTEN OXIDES AND TUNGSTEN BRONZES

摘要: 本文提出了非化学计量钨氧化物中氧指数精确测定的方法。在有KOH存在的情况下,将氧化物或多钨酸盐样品溶于K₃[Fe(CN)₆]溶液中,在氧化-还原反应中,钨被氧化为正六价,Fe(CN)₆^3-定量地被还原为Fe(CN)₆^4-。用重铬酸钾溶液进行滴定,以求出试样中的氧指数(O/W)。
本文进行了分析方法鉴定,并与其他方法,如高锰酸钾容量法进行了对比,结果表明,本法准确度高,操作快速简便。

Abstract: An accurate method for the measurement of the Oxygen index(OI) of non-stoichiometric tungsten oxides was proposed in this paper. In the presence of KOH, tungsten oxide or heterotungstate sample was dissolved in a K₃Fe(CN)₆ solution. In the oxidation-reduction reaction, the tungsten will be oxidized to hexavalent, while the ion Fe(CN)₆^3- in solution will be quantitatively reduced to Fe(CN)₆^4-. By Titrating the Fe(CN)₆ with K₂Cr₂O₇ solution, then OI can be calculated.
An evaluation and error analysis was made in the paper, compared it with·other methods, e.g. the KMnO₄ volumetric method. The results show that the method may be characterized by its high accuracy, simple and quick operation. The method also overcame the shortcomings of the conventional methods.

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