零流电位法在酸碱滴定中的应用研究

摘要

The measurement principle and application of zero current potentiometry in acid-base titration were discussed. Both the ti-trations of weak acid (strong acid) by strong alkaline and weak alkaline (strong alkaline) by strong acid were tested to demonstrate the applicability of zero current potentiometry in acid-base titration. Overall method performance was investigated using the titration of acetic acid by sodium hydroxide. The relative error of this method was-0.4% and the RSD of the same electrode was 0.4% ( n= 5). The RSD of the same electrode for S days successive assays was 0. 6%and the RSD of five electrodes was 0.5%. The experimental results showed that zero current potentiometry exhibits higher accuracy, stability and repeatability.%探讨了零流电位法在酸碱滴定中的检测原理及应用,通过考察强碱滴定弱酸、强碱滴定强酸、强酸滴定弱碱以及强酸滴定强碱四种滴定体系,探明了零流电位法在酸碱滴定中的适用性.通过氢氧化钠滴定醋酸对本方法进行评价,实验结果表明:本法的相对误差为-0.4％,同一根电极的滴定值的相对标准偏差(RSD)为0.4％(n=5),同一根电极五天滴定值的RSD为0.6％,五根电极滴定值的RSD为0.5％.本方法具有较高的准确性、稳定性和重现性.