碳酸钠与碳酸氢钠鉴别实验的教学改进
Teaching Improvement of the Identification Experiment between Sodium Carbonate and Sodium Bicarbonate

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.