化学学报 ›› 1958, Vol. 24 ›› Issue (1): 25-29. 上一篇    下一篇

论文

双铂极电流滴定法同时测定锌和镉

高小霞1, 莊文德2   

  1. 1. 北京大学化学系;
    2. 中国科学院应用化学研究所
  • 投稿日期:1957-04-28 发布日期:2013-06-03

SIMULTANEOUS TITRATIONS OF ZINC AND CADMIUM WITH THE “DEAD-STOP END-POINT”

KAO SHEAU-SHYA1, CHUANG WEN-THE2   

  • Received:1957-04-28 Published:2013-06-03

1.亚铁氰化钾的沉淀反应可用双铂极电流滴定法指示终点, 外加电压以50毫伏为宜.2.在1M盐酸溶液中, 亚铁氰化钾可使锌定量的沉淀为Zn3K2[Fe(CN)6]2, 而镉不干扰.在同一溶液中加入固体硫酸铵使浓度达0.9-1.2M, 则可使镉定量的沉淀为Cd5(NH4)6[Fe(CN)6]4.3.根据以上实验结果, 拟定锌镉共存时的同时测定方法, 并应用於海绵镉的分析得到满意的结果.

1.The "dead-stop" method of Foulk and Bawden has been found very convenient for the determination of the end-point in the precipitation ti七rations with ferrocyanide, if an applied voltage of about 50 millivolts is used.In 1M hydrochloric acid solution, zinc can be precipitated quantitatively by ferrocyanide as Zn3K2[Fe(CN)6]2, while cadmium remains in solution.After adding solid ammonium sulfate(about 9 grams in 60 ml.of solution)cadmium can be quantitatively precipitated as Cd5(NH4)6[Fe(CN)6]4.