When a copper rod is dipped in an aqueous silver nitrate solution, a reaction occurs between the copper and silver nitrate. The color of the solution changes to blue.

To understand why this happens, let`s analyze each option provided:

Option 1 states that Cu is more easily reduced than Ag. In a redox reaction, reduction is the gain of electrons. Since copper is more easily reduced, it means that it prefers to gain electrons and is therefore a stronger reducing agent. As a result, copper ions present in the copper rod will be reduced to copper atoms, while silver ions in the silver nitrate solution will remain as silver ions. This reduction of copper ions results in the color change of the solution to blue, indicating the presence of copper atoms.

Option 2 suggests that Ag is more easily reduced than Cu. However, this is not the case. Copper is more easily reduced than silver, as explained in option 1.

Option 3 states that nitrate ions act as an oxidizing agent. However, the color change in the solution is not due to the oxidizing properties of nitrate ions.

Option 4 suggests that nitrate ions act as a reducing agent. However, this is not the case. The reduction happening in this reaction is due