铌的极谱催化波——Ⅰ铌（Ⅴ）—羥胺—盐酸体系

铌的极谱催化波——Ⅰ铌（Ⅴ）—羥胺—盐酸体系 STUDIES OF POLAROGRAPHIC CATALYTIC WAVES OF NIOBIUM Ⅰ. THE SYSTEM OF NIOBIUM（V）-HYDROXYLAMINEHYDROCHLORIC ACID 佘培柱 first-author 周性尧 曾云鶚 在濃盐酸介質中,当铌（Ⅴ）与羥胺共存时,能产生极譜催化波。在10.0N盐酸、0.40M盐酸羥胺的最宜条件下,铌濃度在1×10 -6 —1×10 -4 M区間,催化电流与铌濃度成直线关系倭康念?Ⅴ)、钛（Ⅳ）、钼（Ⅵ）、钨（Ⅵ）、锆、钍、铀（Ⅵ）等离子存在时,不干扰铌的测定。經催化电流的性質及机理的研究,証明电流完全受化学反应速度所控制,其反应机理系铌（Ⅴ）还原到铌（Ⅳ）后,被羥胺氧化而再生五价铌,重新在滴汞电极上还原。并经測得化学反应的速率常数为5.2×10 2 升/克分子·秒（25℃）。 A polarographic method for the determination of trace amount of niobium based upon its catalytic current is described. In solutions of 10N hydrochloric acid and 0.4M hydroxylamine chlorhydrate, the concentration range of niobium （Ⅴ）is from 1×10 -6 M to 1×10 -4 M, a linear relation exists between catalytic currents and concentrations of niobium. No interference from small amounts of tantalum（Ⅴ）, titanium（Ⅳ）, molybdenum（Ⅵ）, tungsten（Ⅵ）, zirconium,thorium and uranium（Ⅵ） ions is detected.The properties of the catalytic wave have been investigated. This current is controlled by the rate of chemical reaction, of which niobium（Ⅳ） is oxidized by hydroxylamine and niobium（Ⅴ） is regenerated. The velocity constant of the che mical reaction is computed as 5.2×10 2 l/mole.sec （25℃）. 1965-01-01 2021-04-01 Z1