在初中化学教材中，有三个还原氧化铜的实验，即用氢气、木炭粉、一氧化碳来还原氧化铜，试管壁总沉积一层红色的铜，很难清洗。下面介绍一种除掉铜迹的方法。向有铜迹的试管注入少量饱和氢氧化钠溶液，在酒精灯煮沸约２min，红色铜迹很快从试管壁上脱落下来，再用清水洗净即可 In junior high school chemistry textbooks, there are three experiments to reduce the copper oxide, that is, using hydrogen, charcoal powder, carbon monoxide to reduce the copper oxide, the test tube wall is always deposited a layer of red copper, it is difficult to clean. The following describes a method to remove the copper traces. Put a small amount of saturated sodium hydroxide solution into the tube with copper traces, and boil for about 2 minutes in the alcohol lamp. The red copper trace will be quickly detached from the wall of the tube and then rinsed with clean water.