In the redox reaction: Cu + 2AgNO3 → 2Ag + Cu(NO3)2, which substance acts as the oxidizing agent?

• A. Cu
• B. Cu(NO3)2
• C. Ag
• D. AgNO3

Answer: (D)

Verified step by step guidance

1. Identify the oxidation states of the elements in the reactants and products. For copper (Cu) in its elemental form, the oxidation state is 0. For silver (Ag) in AgNO3, the oxidation state is +1.
2. Determine which species is oxidized and which is reduced by comparing the oxidation states before and after the reaction. Copper (Cu) goes from 0 to +2 in Cu(NO3)2, indicating it is oxidized. Silver (Ag) goes from +1 in AgNO3 to 0 in elemental Ag, indicating it is reduced.
3. Recall that the oxidizing agent is the substance that causes oxidation by accepting electrons and is itself reduced. Since silver ions (Ag+) are reduced, the compound containing them, AgNO3, acts as the oxidizing agent.
4. Note that Cu(NO3)2 is a product and does not act as an oxidizing agent in this reaction. Elemental Cu is oxidized, so it cannot be the oxidizing agent.
5. Conclude that AgNO3 is the oxidizing agent because it contains Ag+ ions that gain electrons during the reaction.