为提高学生的学习兴趣,笔者特制作对比实验试管。现作简要介绍。一、特点和用途1.特点。药品的盛放及洗涤方便,实验对比效果明显,对比实验所用时间短。2.用途。可用于在试管中进行的对比实验,如碳酸钠和碳酸氢钠性质的对比实验,浓、稀硫酸性质的对比实验等。二、制作材料实验室所用的规格为20mm×200mm普通大试 In order to improve students' interest in learning, I made a special experiment tube. Now make a brief introduction. First, the characteristics and uses 1. Features. Medicine in full bloom and washing convenience, the experimental contrast effect is obvious, compared with the experimental time is short. 2. Use. Can be used for comparison experiments in test tubes, such as sodium carbonate and sodium bicarbonate nature of the comparative experiment, concentrated, dilute sulfuric acid nature of the comparative experiment. Second, the material used in the laboratory specifications for the 20mm × 200mm ordinary test