单水氢氧化锂中氢氧化锂含量的不确定度评定

Evaluation of Uncertainty in Determination of Lithium Hydroxide by Acid-Alkali Titration

本文采用酸碱滴定法测定单水氢氧化锂中氢氧化锂的含量,对结果的不确定度进行评定。采用酸碱滴定法,建立数学模型,分析不确定度来源。各不确定度来源主要为盐酸标准滴定液浓度、滴定体积、摩尔质量、称样试料、重复测量,其中盐酸标准滴定液浓度、称样试料和滴定体积对不确定度影响较大。本次测定中氢氧化锂测定结果可表示为(57.33±0.19)%,k=2。

The content of lithium hydroxide in lithium hydroxide monohydrate is determined by acid-alkali titration,and the uncertainty of the results is evaluated.According to acid-alkali titrimetric method,the mathematical model is established to analyze the source of uncertainty.The main sources of uncertainty include concentration of hydrochloric acid standard titrant,titration volume,molar mass,sample weighing and repeated measurement,among which the concentration of hydrochloric acid standard titrant,sample weighing and titration volume have a greater impact on the uncertainty.The determination result of lithium hydroxide in this determination can be expressed as(57.33±0.19)%,k=2.