两种方法对于氢氧化钠溶液标定不确定度影响的比较

Comparison of Influence of Two Different Preparation Methods on Uncertainty in Calibration Process of Sodium Hydroxide Solution

利用《化学试剂标准溶液的制备》和《测量不确定度评定与表示》对两种方法中产生的标准不确定度进行计算,对两种不同配制邻苯二甲酸氢钾基准溶液方法(固体称量法和液体移取法)对于氢氧化钠溶液浓度标定产生的不确定度进行了比较。结果表明:固体称量法和液体移取法的合成标准不确定度分别为2.343×10^(-3)和3.750×10^(-3),在氢氧化钠标定的方法中,用固体称量法,直接称量一定质量邻苯二甲酸氢钾加蒸馏水溶解配制溶液所产生的最后滴定误差更小。

The uncertainty of two different preparation methods of potassium hydrogen phthalate reference solution(solid weighing method and liquid transfer method)was compared for the concentration calibration of sodium hydroxide solution.The standard uncertainty generated in the two methods by using the Preparation of Chemical Reagent Standard Solution and Evaluation and Expression of Measurement Uncertainty was calculated.The combined standard uncertainty for solid weighing method and liquid transfer method were 2.343×10^(-3) and 3.750×10^(-3).In the calibration method of sodium hydroxide,the final titration error caused by directly weighing a certain mass of potassium hydrogen phthalate and dissolving it in distilled water by solid weighing method was smaller.