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在做浓硫酸与铜反应演示实验时,我们常常遇到这样的现象,即在实验过程中看不到溶液变蓝色,试管底部出现黑色和灰白色沉淀,无法向学生解释,形成比较尴尬的场面,只能草草结束。为了弄清实验事实,笔者进行了探究实验。一、实验步骤1.将铜片加入到浓硫酸中,加热。现象:一是铜片表面迅速变黑,溶液出现浅蓝色,
In doing concentrated sulfuric acid and copper reaction demonstration experiment, we often encounter such a phenomenon that in the experiment can not see the solution turns blue, the bottom of the tube appears black and gray precipitate, can not explain to students, the formation of more awkward scenes , Can only overworked. In order to clarify the experimental facts, the author conducted exploratory experiments. First, the experimental steps 1. The copper was added to the concentrated sulfuric acid, heated. Phenomenon: First, the rapid blackening of copper surface, the solution appears light blue,