希托夫法测定离子迁移数实验的教学改革研究

Determining Ion Transference Numbers Using the Hittorf Method:A Study on Experimental Teaching Improvement

希托夫法是物理化学实验中测定离子迁移数的传统方法。在教学实践中发现,传统实验装置及操作方法易因待测溶液对流、扩散或人为操作失误等问题导致测定的离子迁移数不准确,因此有必要改进该实验的装置和操作方法。本文提出通过调整测量装置中U型迁移管的玻璃活塞数量,改进装液、溶液收集、滴定操作等实验步骤,降低实验操作难度,增加同批样品的滴定分析次数,提高实验结果的准确性。同时减少近70%的废液产生量,降低了教学成本,减少了环境污染。本研究能够激发学生的实验研究创新意识,促其建立污染物减排的环保观念。

The Hittorf method is a traditional method for determining ion transference numbers in physical chemistry experiments.During practice,it was found that the traditional experimental device and operation method frequently caused inaccurate ion transference numbers to be obtained owing to human error and/or the convection and diffusion of the solution.Therefore,it is necessary to improve the device and operation method of this experiment.Herein,we propose adjusting the number of glass pistons in the three-chamber ion-transfer tube and improving the experimental steps,including liquid loading,solution collection,and titration operation.This proposed work would reduce the difficulty of experimental execution,increase the number of titration analyses,and improve the accuracy of the overall experiment.Simultaneously,the formation of liquid waste could be reduced by approximately 70%,resulting in significant cost reduction and environmental protection.This study could also stimulate students’innovative consciousness of experimental research and encourage them to develop an environmental protection perception.