基于模块化教学模式的铬离子鉴定方法的优化研究

A Study on the Optimization of the Identification Method of Chromium Ion Based on Modularization Teaching

混合阳离子Ⅰ(Al3+、Zn2+、Cr3+、Mn2+、Fe3+、Co2+、Ni2+)的定性分析是大学无机化学实验具有代表性的实验内容。在传统的教学模式下,学生按照课本内容进行实验,学习效果欠佳,且往往在鉴定Cr3+时存在结果现象不明显、实验检出率低等问题。本文将模块化思想融入到该实验课堂教学中,并在实验过程中引导学生根据问题所在,自主分组设计方案,对鉴定方法的影响因素如酸度、过氧化氢用量等进行了探究,通过对实验条件的优化和改进,有效地解决了实验过程中Cr3+难以鉴定的问题,提高了实验的成功率的同时,也激发了学生的积极性和独立研究能力,提高其综合实验素质,较大地改善了课堂效率和教学质量。

The qualitative analysis of mixed cations Ⅰ(Al3+, Zn2+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+) is the representative content of inorganic chemistry experiment in university. Under the traditional teaching mode, Most students learn not well because they usually just carry out the experiments according to the produces of the textbook. On the other hand, some problems arise in the experiment process of the qualitative determination of Cr3+, such as the phenomenon of the result is not obvious and the detection rate is low and so on. In this study, the modularization thought is integrated into the experimental teaching. And the students are guided to analyze and design their own scheme in groups according to the existing problems. The influencing factors such as acidity and the amount of hydrogen peroxide used in the identification method are investigated. Through the optimization and improvement of the experimental conditions, the problem that Cr3+ is difficult to identify in the course of the experiment is effectively solved, and the success rate of the experiment is improved. Besides, the modular experiment teaching arouse the enthusiasm and independent research ability of the students, improve their comprehensive experimental quality, and also make the classroom efficiency and teaching quality improve greatly.