论文部分内容阅读
人教版化学必修2中“钠与无水乙醇反应”实验采用在一支试管中加入无水乙醇和金属钠,塞上带有针头的橡胶塞,先收集一试管气体验纯后再点燃的方法,以验证所生成的气体是否是氢气(图1)。然而,笔者在教学中发现,因为产生的氢气量少,验纯收集很难,且几乎不能点燃氢气,更看不见持续燃烧的现象,所以用干燥的烧杯罩其上方观察现象难以实现。为此,笔者进行了如下探索和改进。一、装置选择
PEP 2 chemistry “sodium and ethanol reaction ” experiment in a test tube by adding ethanol and sodium metal, plug the needle with a rubber stopper, the first collection of test tube gas pure experience before Ignite the method to verify that the gas generated is hydrogen (Figure 1). However, the author found in teaching that because of the small amount of hydrogen produced, it is very difficult to collect pure hydrogen, and almost can not ignite hydrogen gas. The phenomenon of continuous burning can not be seen. Therefore, it is difficult to observe the phenomenon with a dry beaker. To this end, I conducted the following exploration and improvement. First, the device selection