图示法推导标准电极电势与平衡常数关系初探

Preliminary Exploration for Deducing Relationship between Standard Electrode Potential and Equilibrium Constant by Graphic Method

大一新生在进行弱电解质、难溶电解质及配离子所形成的电对的标准电极电势计算时存在畏难心理,且学习效果不理想。针对这些问题,本文探索了使用图示的方法推导这三种电对的标准电极电势与其平衡常数的关系。这一推导方法简单、直观、学生一目了然,容易掌握,并且突出了浓度对电极电势的影响,即能斯特方程的应用氧化还原平衡这一教学重点。实践证明,使用这种方法教学,学生能更好的掌握这些电对标准电极电势的计算,教学效果也有明显提高。

College freshman have some fearful psychologies in calculating the standard electrode potentials of the redox couples related to the weak electrolytes, insoluble electrolytes and coordination ions, and the learning effect has been far from ideal. To solve these problems, graphic method was employed for deducing the relationship between the standard electrode potentials of these kinds of redox couples and their equilibrium constant. This method was simple and clear, and it was easy to master and manifest at a glance. More importantly, the concentration influencing on the standard electrode potential can be demonstrated more fully by this method, i.e., the teaching point for Nernst equation applicate to the chemical equilibrium was highlighted more effectively. According to the results from the practical teaching, it was concluded that students can proficiently master the calculation of the electrode potentials of these redox couples, and the teaching effect was improved obviously.