Please based on the experiment procedures, to match the reaction of two substances with the Observations.
2 v Cu(NO3)2 + NaOH
4 v CuSO4 + Mg
1 v Cu + HNO3
v CuO + H2SO4
3 v Heating Cu(OH)2
1. Orange gas forming, the copper is dissolving, and the solution is turning blue
2. A Blue precipitate is forming
3. The black precipitate is generated
4. The precipitate disolves, and the solution turns blue color
5. The burgundy/orange solids/precipitate generated, there is bubbling on the top of solution