部颁九年义务教育初中化学全一册以实验 [1—6]、[1— 7]、[1— 8]来说明二氧化锰的催化作用 ,虽然实验步骤分明、有条理 ,但占用课堂时间较多、试剂用量较大。为此 ,我们将其改为微型实验。改进后 ,不但一次可完成上述三个实验所要表达的内容 ,而且大大缩短了实验时间 ,并使试 The ministry’s nine-year compulsory education junior high school chemistry is based on experiments [1-6], [1-1-7], and [1-8] to illustrate the catalytic role of manganese dioxide. Although the experimental procedures are clear and organized, they occupy the classroom. More time and reagents are used. To this end, we changed it to a miniature experiment. After the improvement, not only can the contents of the above three experiments be expressed at one time, but also the experimental time can be greatly shortened and the test can be conducted.