滴定分析中误差正负判断的新方法

New Method of Determining the Positive and Negative Errors in Titration Analysis

滴定分析中的误差有正有负。通常情况下,在进行误差分析时,把引起误差的各种因素转化为消耗的滴定剂的体积变化,再来确定最后分析结果误差的正负。使用该法时,一般要进行变量转换,学生时常出错。本文介绍的方法是:先列出待测结果的计算公式,再找出公式中存在问题(即有偏差)的代入项,比较其与真实值(或有效值)的大小,最后由公式判定待测结果误差的正负。学生用此方法判断滴定分析中误差的正负,结果快速而准确,展示了该方法的实效性。

The error in titration analysis can be positive or negative. Usually, when making error analysis, various factors that may contribute errors can be transformed into volume changes of titrant consumption, and then determine the positive or negative error of the final analysis re- sult. The mentioned method above typically involves lots of variable transformation which can be tedious and error prone. This paper introduces another method. First, list the formulas for re- sults calculation, then find the deviation data and see whether it＇s above or below the true value （or actual value）, that way the final result can be determined just by the formula calculation. Students can use the above method to determine the positive and negative errors in titration in a much faster and more accurate way. This also demonstrates the effectiveness of the method.