Oxidation potential of Aluminium is greater than copper ,in aluminium nitrate Aluminium is in plus 3 oxidation State .since, oxidation potential of Aluminium is greater than copper so copper can't reduce aluminium so there is no effect so, no reaction take place.

Introduction:
The electrochemical series is a list of metals arranged in order of their decreasing electropositive character. Electropositivity refers to the tendency of a metal to lose electrons and form positive ions. The given electrochemical series is Mg > Zn > Cu > Ag, which means that magnesium is the most electropositive metal, followed by zinc, copper, and silver.

Explanation:
When a copper spoon is used to stir a solution of aluminium nitrate, a redox reaction takes place due to the difference in electropositive character between copper and aluminium.

1. Displacement reaction:
Copper is less electropositive than aluminium, so it cannot displace aluminium from its compound. Therefore, no displacement reaction occurs between copper and aluminium nitrate.

2. Formation of copper nitrate:
As the copper spoon comes into contact with the aluminium nitrate solution, it will react with the nitrate ions present in the solution. Copper will displace the nitrate ion and form copper nitrate.

3. No reaction with aluminium:
Since copper is less electropositive than aluminium, it cannot displace aluminium from its compound. Therefore, no reaction will occur between copper and aluminium in the solution.

4. Solution remains unchanged:
The solution of aluminium nitrate will remain unchanged as copper does not react with aluminium. The copper spoon will gradually dissolve into the solution, forming copper nitrate.

5. Formation of copper oxide:
If the solution is heated, the copper nitrate will decompose to form copper oxide. This occurs because nitrate ions are unstable at high temperatures and decompose into oxides.

Conclusion:
In summary, when a copper spoon is used to stir a solution of aluminium nitrate, no reaction occurs between copper and aluminium. Copper reacts with the nitrate ions in the solution to form copper nitrate. The solution of aluminium nitrate remains unchanged, while the copper spoon gradually dissolves into the solution.