一、试管壁上做凹坑现用初三化学教材中 ,演示“二氧化锰对氯酸钾分解的催化作用”的实验时 ,用三支试管做实验 ,其中用两支试管分别给二氧化锰和氯酸钾加热 ,以带火星木条证明未放出氧气以后 ,将二氧化锰倒入氯酸钾 ,再用带火星木条证明放出了大量氧气 ,这样做不免费时费力。 First, the wall of the test tube is made of pits. The third grade chemistry textbook is used to demonstrate the experiment of “catalytic action of manganese dioxide on the decomposition of potassium chlorate”. Three tubes are used for experiments. Two manganese tubes are used to give manganese dioxide. After heating with potassium chlorate to prove that the Martian wood strips have not released oxygen, pour the manganese dioxide into potassium chlorate, and then use the Martian wood strip to prove that a lot of oxygen is released. This is not free and laborious.