一、情景描述在硝酸氧化性的教学中,新教材安排了如图1所示的实验。在甲、乙装置的左侧两只试管中各放人一小块铜片,分别加入少量浓硝酸和稀硝酸,立即用带导管的胶塞塞住试管口,并将导管通入另一盛有 NaOH 溶液的试管,观察发生的现象。反应片刻后,加入浓硝酸的试管反应剧烈,产生红棕色气体;加入稀硝酸的试管反应缓慢,气体无色,取下试管上的胶塞,使空气进入试管,观察发生的现象…… First, the scene described In nitric acid oxidation teaching, the new textbook arranged as shown in Figure 1 experiments. A, B in the left side of the two test tubes were put in a small piece of copper, were added a small amount of concentrated nitric acid and dilute nitric acid, immediately with a plug with a plug the test tube port, and the catheter into the other Sheng Test tube with NaOH solution and observe what happens. After the reaction for a while, the tube with concentrated nitric acid reacted violently to produce a reddish brown gas; the tube with dilute nitric acid was slowly reacted and the gas was colorless; the rubber plug was removed from the tube to allow air to enter the tube and observed the phenomenon.