九年级中学教科书化学全一册中分组实验“氢气的制取和性质”按教材中的实验程序操作有以下弊端: 1:氢气的可燃性实验火焰太小,现象不明显。2:火焰为黄色不是淡蓝色给学生造成误会。3:反应不能随时发生随时停止,浪费药品。4:若药品不足时需要增加程序浪费时间。 The ninth grade chemistry textbook chemistry a group of experiments “hydrogen preparation and nature” according to the experimental procedures in the textbook operation has the following drawbacks: 1: flammable hydrogen flame test is too small, the phenomenon is not obvious. 2: The flame is yellow, not light blue to students misunderstanding. 3: The reaction can not stop anytime, waste medicine. 4: If the drug is insufficient, you need to increase the program to waste time.