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化学学报
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化学学报 ›› 1964, Vol. 30 ›› Issue (2): 230-232. 上一篇    下一篇

研究简报

电流滴定法测定钨

张悌衡, 曹斐云, 束世明   

  1. 唐山铁道学院
  • 投稿日期:1963-05-24 发布日期:2013-06-03

AMPEROMETRIC TITRATION OF TUNGSTEN WITH EDTA

CHANG T'I-HENG, TSAO FEI-YÜN, SHU SHIH-MING   

  • Received:1963-05-24 Published:2013-06-03

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被引次数

1

矿石中钨的重量法测定较繁.络合滴定直接法测钨尚不够完善[1].间接法测定钨是将试液中钨酸根以钙盐[2]、钡盐[3]或铅盐[4]形式析出,然后用EDTA滴定钙、钡或铅,其中以测定后者的结果较好.以化学法指示络合滴定的终点常因金属指示剂选择或滴定条件控制不当,滴定达终点时指示剂变色往往不够清晰,影响滴定精确度.络合滴定可采用安培法(电流滴定)指示终点[5].

Disodium EDTA is used in an indirect method for the amperometric titration of tungsten in minerals.This is based on the precipitation of tungsten as lead tungstate.The precipitate is dissolved in 1 M sodium hydroxide and 1 M sodium tartrate.The latter serves also as a supporting electrolyte.Titrate lead ions with 0.05 M disodium EDTA at -0.70 to -0.80 volt in NH3-NH4Cl buffer solution.The amount of tungsten can then be found by calculation.The results found are comparable to those found with ammonium nitrate method.