亚硝酸钠滴定法中指示终点方法的改进

Improved Method of Indicating the End of Sodium Nitrite Titration Method

目前亚硝酸钠法指示终点的方法多采用永停滴定法或外指示剂法，这2种方法在实际操作过程中都存在一定的缺陷。经过多年教学实践，对亚硝酸钠法指示终点的方法做一点改进，采用内指示剂和外指示剂结合的方法，改进后的实验测定结果的相对平均偏差很小，而且实验快速、操作简单，经济、实用。

Currently, indicating the end of sodium nitrite method mostly use dead stop titra- tion and external indicator method, the two methods have some defects in the actual operation process. During teaching practice, the end indication method is improved by combining internal indicator with external indicator. Improved method can make the relative average deviation smal- ler, and experiment operation more simple and faster, so the experiment becomes more economic and practical.