Study on the concentration of nitric acid in reaction of copper with nitric acid

There are many insufficiencies in the demonstration experiment of copper reaction with nitric acid in grade two of senior chemistry.By improving experimental method and device,which using moveable copper sheet instead of brass wires,the concentration of nitric acid is explored.The results show that when the concentration of nitric acid is 4.8 mol/L,the reaction time is shorter,the experimental phenomenon is more obvious and the teaching effect is better.