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在“氧气的制法”这一节中,有的学生观察到过氧化氢在不加二氧化锰的情况下试剂瓶壁上就有气泡产生(该现象在教科书上没有提及),于是提出疑问,这些气泡是不是氧气呢?通过进一步探究发现,给过氧化氢溶液微热可看到有较多的气泡冒出,而用带火星的小木条检验却不能复燃,此时教师对出现此现象的各种推理、解释都将显得苍白无力,亦有武断的嫌疑。于是我故意提出问题:该试管中放出的气体是不是氧气?我们该怎么验证呢?有的学生说,应该收集起来再用带火星的小木条检验,我问为什么要这样做?学生说,如果氧气的量太少的话,比如空气中有氧
In the section “How to Make Oxygen”, some students observed that hydrogen peroxide generated bubbles in the reagent bottle wall without adding manganese dioxide (a phenomenon not mentioned in textbooks) So ask questions, these bubbles are not oxygen? Through further exploration found that, to the hydrogen peroxide solution can be seen slightly hot microbubbles pops up, but with a small piece of test with Mars can not be rekindled, this time the teacher All kinds of reasoning and explanation for this phenomenon will appear pale and weak and arbitrary judgments. So I deliberately asked the question: Is the gas released in the test tube oxygen? How can we verify it? Some students say that they should be collected and then tested on a small log with Mars. I asked why I did this. If the amount of oxygen is too small, such as aerobic in the air