过氧化氢水溶液中过氧化氢含量分析的简便方法

DETERMINATION OF CONTENTS OF H_2O_2 IN ITS AQUEOUS SOLUTION BY DENSITY METHOD

用氧化还原滴定法测过氧化氢含量 ,是测定过氧化氢含量的经典方法 ,但存在着影响因素多 ,操作周期长 ,分析费时、费力的缺点。此法根据不同浓度的过氧化氢水溶液同一温度下的密度差别来分析过氧化氢水溶液中过氧化氢含量 ,分析了其可靠性 ,指出该方法具有准确、简便。

The density method was proposed for the determination of concentration of H 2O 2 of its aqueous solution. The density of the unknown sample was firstly found by the weighing method as compared with the density of pure water at 25℃. And then the concentration of H 2O 2 in the aqueous sample solution (in mass percentage) was calculated by the extrapolation method using the known data obtained from the coversion table of concentration of H 2O 2 in aqueous solution to the corresponding density. For instance, the density (ρ) of an unknown H 2O 2 solution was found to be 1.1025g·ml -1. As found from the conversion table, the density values 1.0694g·ml -1 [for w(H 2O 2)=20%] and 1.1081g·ml -1[for w(H 2O 2)=30%] were two nearest values adjacent to 1.1025g·ml -1. Based on these known data, the concentration of H 2O 2 in the unknown solution was calculated by extrapolation method. The density method was proved to be more convenient, accurate and easier to be used in routine or control or analysis as compared with the convertional KMnO 4 titrimetric method.