碳酸钠与碳酸氢钠鉴别实验的教学改进

本文通过三种方法鉴别碳酸钠与碳酸氢钠,经过实验发现用氯化钡鉴别二者,实验现象不明显。采用盐酸溶液鉴别碳酸钠与碳酸氢钠,根据反应的程度,与产生二氧化碳气体的量能鉴别二者,但是反应条件难以控制。经改进采用U型装入碳酸钠与碳酸氢钠溶液,用注射剂控制盐酸的滴加速率及反应同步,根据装置中气球的变化速率及量,来鉴别二者。改进的鉴别实验,实验现象明显,便于学生区分碳酸钠与碳酸氢钠。In this paper, three methods are used to identify sodium carbonate and sodium bicarbonate. After experiments, it is found that barium chloride is used to identify the two, and the experimental phenomenon is not obvious. Sodium carbonate and sodium bicarbonate are identified by hydrochloric acid solution. According to the degree of reaction, they can be identified by the amount of carbon dioxide gas produced, but the reaction conditions are difficult to control. After improvement, sodium carbonate and sodium bicarbonate solutions were loaded in a U-type, and the drop acceleration rate and reaction synchronization of hydrochloric acid were controlled by injection. The two were identified according to the change rate and amount of balloons in the device. The improved identification experiment has obvious experimental phenomena, which is convenient for students to distinguish sodium carbonate from sodium bicarbonate.

浅谈任务驱动教学在高中化学实验课堂的应用

本文对任务驱动教学模式进行简单解释的基础上,从高中化学实验教学现状开始分析,列举出了适合该教学模式下的教学原则,并从教学分析的角度对课程标准、教材、学情和教学设计进行了详细的分析讨论。还对任务驱动教学模式下高中化学实验课程的原则和策略进行了详细的说明。高中化学实验教学在任务驱动模式下,学生的学习兴趣、积极性得到了明显的改善,每一位学生都有了在课堂展示自己的机会,不管是学生个人能力还是团队协作能力都得到了显著的增强。在教师精心设计的情境任务中,学生通过小组合作,在团队协作中,学生的自我表达能力也得到了提高,学生们普遍更加自信起来。