Acta Chimica Sinica ›› 1965, Vol. 31 ›› Issue (5): 428-431. Previous Articles     Next Articles

交流示波极谱滴定的研究——Ⅱ.用铬酸钾滴定常量铅

高鴻, 彭慈貞, 張文彬   

  1. 南京大学化学系
  • 投稿日期:1964-07-24 发布日期:2013-06-03

INVESTIGATIONS ON A. C. OSCILLOGRAPHIC POLAROGRAPHIC TITRATION Ⅱ. TITRATION OF MACRO QUANTITIES OF LEAD BY POTASSIUM CHROMATE

KAO HUNG, PENG CI-ZHEN, CHANG WEN-BIN   

  1. Department of Chemistry, Nanking University
  • Received:1964-07-24 Published:2013-06-03

In this paper, it has been shown that the alternating current oscillographic polaro-graphic titration (i.e. the polarographic titration using dE/dt=f (E) curve to indicate the equivalence point) can be applied to determine macro quantities of depolariser with an accuracy similar to that obtained by ordinary volumetric methods. In 30-50 ml of 0.1 M ammonium acetate solution, 20 to 98 milligrams of lead can be titrated by potassium chromate solution with an average error of 0.2 per cent. Calcium, Mg, Zn, Cd, Co, Ni and Mn do not interfere, while Sn, Sb, Ba and Fe do. Copper, Al and Bi interfete only when present in large amounts. The end point is indicated by the disappearance of the cathode incision of lead, and is very sharp. This method was applied to determine lead in white metal and aluminum alloy with satisfactory results.