实验室制取氧气实验的一个“谎言”

• 作 者: 林子谦
• 机 构: 湖南省长沙市一中高2013级20班,
• 出 处: 实验教学与仪器
• 发表日期: 2015年10期
• 关键词: 氯酸钾 二氧化锰

在九年级化学中,实验室制取氧气实验既是新课程标准要求的8个必做实验之一,也是初中毕业会考中关于气体制取的重点知识。对于用加热氯酸钾和二氧化锰的混合物(或高锰酸钾)并用排水法收集氧气的实验,教材和各类中考题及复习资料都对结束实验前的步骤予以特别要求:只有先将导管从水槽移出水面后,才能熄灭酒精灯,停止加热,否则将导致水槽内液体倒流回试管,从而使试管炸裂。一次,在制取氧气的实验过程中,由于我们的大

In the ninth grade chemistry, the laboratory oxygen experiment is not only one of the eight required experiments in the new curriculum standard, but also the key knowledge about the gas preparation in the junior high school graduation examinations. For experiments, materials and various mid-term exams and review materials that use a mixture of potassium chlorate and manganese dioxide (or potassium permanganate) and drain water to collect oxygen, special requirements are placed prior to the conclusion of the experiment: After the sink is removed from the water, the alcohol lamp can be extinguished and the heating stopped. Otherwise, the liquid in the sink will flow back into the tube, causing the tube to burst. Once, in the process of making oxygen experiment, due to our big