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人民教育出版社出版的化学教材第27页,也就是测定空气里氧气含量的实验设计,教材中的实验设计内容是:在集气瓶内加入少量的水,并做好记号。用弹簧夹夹紧乳胶管,点燃燃烧室内的红磷后,立即伸入瓶中并把塞子塞紧。观察红磷燃烧的现象。待红磷熄灭并冷却后,打开弹簧夹,观察实验现象及水面变化情况。通过观察发现水位上升五分之一。实验分析:(1)氧气约占空的五分之一是事实。(2)教材中的实验在操作过程中有几处气密性的
People’s Education Press published chemical textbook Page 27, which is measured in the air of oxygen experimental design, the experimental design of the textbook content is: add a small amount of water in the gas collection bottle, and make a mark. Clamp the latex tube with the spring clip, ignite the red phosphorus in the combustion chamber, immediately into the bottle and plug the plug. Observe the phenomenon of red phosphorus combustion. Red phosphorus to be extinguished and cooled, open the spring clip to observe the experimental phenomena and changes in the water. Observed by the observation that the water level rise one-fifth. Experimental Analysis: (1) About a fifth of oxygen is a fact. (2) experimental teaching materials in the course of several gas tightness