高锰酸钾溶液的标定及其常见影响因素分析

Calibration of potassium hypermanganate solution and analysis of its common influencing factors

用两种不同基准物质(硫代硫酸钠标准溶液、草酸钠)对同批次高锰酸钾溶液分别进行标定。结果表明,两组实验结果各自保持平行,未超出平行测定的最大允许误差(0.2%),并且两组实验数据也保持平行,平行测定误差为0.16%,标定浓度分别为0.101 57 mol/L和0.101 54 mol/L。同时分析了影响实验结果的常见因素,如玻璃器具的挂壁、试剂不纯、环境的影响、辅助试剂的影响、实验人员的影响以及滴定速度、温度的影响。实验结果表明,在光线较好的晴朗天气下排除以上影响因素,可以保证多次实验结果的平行,并且不超出平行测定的允许误差。

Calibration experiments of potassium hypermanganate solution were done based on different reference materials,standard solution of sodium thiosulfate and sodium oxalate,respectively. The result showed that two experiments result kept parallel respectively and under maximal allowed error of parallel tests（ 0. 2%）. The samples done under two different reference materials kept parallel as well and the parallel test error is 0. 16%. Final results are 0. 101 57 mol/L and 0. 101 54 mol/L. Meanwhile,some analysis about common influencing factors of calibration of potassium hypermanganate solution were given,such as solution adhension phenonmenon,impurity of reagent,environment,auxiliary reagents,experimenters,titration velocity and temperature. The results also show that experiments can reach parallel and final result can be kept within allowed error range of parallel tests on sunny days with a good vision but excluding those mentioned influencing factors.