论文部分内容阅读
部编高中化学课本第一册第十三页〔实验1—5〕,看上去简单,做起来也容易,但不掌握好条件,就得不到好的效果。我经过反复实验,感到铜片的大小、反应温度和硫酸浓度对此实验有影响,现分述如下:一、铜片的大小为什么要用铜片和浓硫酸而不用铜粉和浓硫酸进行此实验呢?如果用铜粉进行实验,在加热时,一方面铜粉悬浮于硫酸中,影响硫酸铜溶液的观察;另一方面,液体很快变黑,再加入硝酸有淡黄色的硫析出,所以黑色沉淀为硫化铜或硫化亚铜。以课本上的方法进行实验,取一块大于1cm~2 厚1.5mm 的铜片进行实验,加热
The Department edits the first volume of Chemistry Book 1 of the Senior High School (Experiment 1-5). It looks simple and easy to do, but without good conditions, good results cannot be obtained. After repeated experiments, I felt that the copper size, reaction temperature, and sulfuric acid concentration had an effect on this experiment. I have now described the following: 1. Size of the copper sheet. Why use copper and concentrated sulfuric acid instead of copper powder and concentrated sulfuric acid? In the experiment, if copper powder is used for experiments, on the one hand, the copper powder is suspended in sulfuric acid to affect the observation of the copper sulfate solution; on the other hand, the liquid turns black quickly, and then nitric acid is added to light yellow sulfur to precipitate. So the black precipitate is copper sulfide or cuprous sulfide. Experiment with the textbook method, take a piece of copper with a thickness greater than 1cm~2 and a thickness of 1.5mm for experimentation.