碘量滴定法测定过氧化氢溶液浓度的改进

MODIFICATION OF THE IODOMETRIC DETERMINATION OF CONCENTRATION OF HYDROGEN PEROXIDE SOLUTION

研究了用碘量滴定法测定过氧化氢浓度时 ,试剂的加入顺序和放置时间对测定结果的影响。结果表明 ,在用碘量滴定法测定过氧化氢浓度的过程中 ,酸化条件下 ,I- 与H2 O2 反应的最佳时间为 5 10min。与高锰酸钾氧化法相比 ,碘量法测定效果较好一些。

The optimum condition for the iodometric determination of concentration of hydrogen peroxide solutions was critically studied and it was found that the sample solution should be acidified with dilute sulfuric acid before the addition of potassium iodide, and that the solution should to stay for 5 to 10min, but not longer than 10min, before the titration with Na_2S_2O_3 titrating solution. Under this condition, hydrogen peroxide reacts completely with iodide to liberate I_2, without any side reactions. The results obtained by iodometric titration were in consistency with the results obtained by the standard method of KMnO_4 titration. But the iodometric method has the advantage of elimination from the interferences of some stabilizing agents which are commonly added to the hydrogen peroxide solution.