Redox Reactions

Step 1: Nature of reaction.
When a copper rod is dipped into AgNO solution, a redox reaction takes place. Copper is more reactive than silver and displaces it from silver nitrate solution.
Step 2: Chemical reaction.
Step 3: Explanation of colour change.
- Cu(NO ) is formed in the solution, which contains Cu ions.
- Cu ions impart a blue colour to the solution.
- Silver metal (Ag) is deposited on the surface of the copper rod.
Conclusion:
The solution turns blue because Cu ions are formed in solution, and silver gets deposited on the copper rod.