摘要
在被测弱酸或弱碱溶液中加入一定量过量ＮａＯＨ或ＨＣｌ标准溶液，再返滴入ＨＣｌ或ＮａＯＨ标准溶液若干次（如５次），依次测定ｐＨ玻璃电极在被测溶液中的电极电位。根据有关酸碱平衡和物料平衡及非线性回归原理对实验数据进行处理。用牛顿法对非线性回归进行简化计算。以模拟数据研究了选点问题。本方法的突出优点是不需要活度与浓度的换算，不需要另行测定工作曲线。测定了ＮａＡｃ和（ＮＨ＿４）＿２ＳＯ＿４等弱酸弱碱，结果今人满意。
A given amount of excess NaOH or HClstandardsolution is added into the weak acidsohtion or tbe weak base sohtion to be deter-mined.Back dropping addition of HCl orNaOH standard solution is carried out a fewtimes(e,g,five times).After each addition ofthe standard soiution,the potential of a pHglass electrode inserted in the solution is mea-sured.According to relatedacH-base equilib-rium,material balance and the principle ofnonlinear regressiOn,the experimental data areprocessed.The nonlinear regression is simplyhandled withNewton's method.The selectionof titration points was stuied with simulateddata. The method has some prominent advan-tages such as not requiring activity-concen-tration conversiOn and not requiring the soledeterminatiOn of relation between potentialand log [H] .The method has been applied tothe determinations of NaAc,(NH_4)_2SO_4 and soon with RSD of 0.11%～0.37%(n=3)。
出处
《分析试验室》
CAS
CSCD
北大核心
1996年第5期15-18,共4页
Chinese Journal of Analysis Laboratory
关键词
弱酸
弱碱
电位法
非线性回归
eak acid:weakbase:Poten-tiometry
Nonlinear regression
