化学学报 ›› 1965, Vol. 31 ›› Issue (1): 86-90. 上一篇    下一篇

论文

库仑滴定剂三价钒

左宗杞, 朱彭龄   

  1. 兰州大学化学系
  • 投稿日期:1963-12-16 修回日期:1963-10-17 发布日期:2013-06-03

TRIVALENT VANADIUM AS COULOMETRIC INTERMEDIATE

TSO TSONG-CHI, CHU PUN-LING   

  1. Chemistry Department, Lanchow University
  • Received:1963-12-16 Revised:1963-10-17 Published:2013-06-03

五、四、三和二等价的钒均已用作容量分析中的滴定剂[1],而用作库仑滴定剂的则只有五价和四价[2,3].本工作探讨低价钒作为库仑滴定剂的可能.在酸性溶液中氧钒离子在铂电极上还原到三价钒的超电压大,在氢离子放电之前,氧钒离子无显著的电极还原[4].

Trivalent vanadium electrogenerated from tetravalent vanadium at the mercury cathode has been used as a coulometric intermediate.In sodium acetate-hydrochloric acid buffer solution of about pH 3, the current efficiency was found to be near 100%.Milligram quantities of Fe(Ⅲ), Ⅴ(Ⅴ), Cr(Ⅵ), and Mn(Ⅶ) were titrated with electro-generated Ⅴ(Ⅲ), with dead-stop end point detection, the relative errors being less than 1%.Evidently oxidants with potentials higher than that of mercury can be determined coulometrically at the mercury cathode.