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一天,化学老师在课堂上做了一个非常精彩的演示实验.老师事先准备了一个广口玻璃瓶,在瓶底铺一层细沙,将瓶里装满纯氧,瓶口用一块平面玻璃盖住.然后,老师把一根火柴缠绕在一段细铁丝上,同时将铁丝的另一端固定在燃烧匙的端部.老师说:“铁丝在空气中用酒精灯加热,可以把铁丝烧得红红的,温度至少有500℃.但是冷却下来以后,铁丝的外面常常包着一层黑色的氧化膜,而内部的铁丝基本没有发生什么变化.那么,如果将铁丝在纯氧中加热,产生的现象是否和在空气中相同呢?”带着这个疑问,老师和同学们一起开始了今天的实验.老师先用酒精灯把缠在细铁丝上的火柴点着,然后推开盖在广口瓶上的平面玻璃,把燃着的火
One day, a chemistry teacher did a very good demonstration experiment in the classroom.The teacher prepared a wide-mouth glass bottle in advance, spread a thin layer of sand on the bottom of the bottle and filled the bottle with pure oxygen. The bottle mouth was covered with a flat glass cover Then the teacher wrapped a match on a thin wire, while fixing the other end of the wire to the end of the burning spoon. “The iron wire is heated in the air with an alcohol lamp to burn the wire red Red, and the temperature is at least 500 ° C. However, after cooling down, the outside of the wire is usually covered with a black oxide film, and the inside of the wire does not substantially change.And then, if the wire is heated in pure oxygen, Is the phenomenon the same as in the air? ”With this question, the teacher and his classmates started the experiment today, with the alcohol lamp, the teacher lit the match on a thin wire, Flat glass on the bottle, putting a burning fire