Identifying oxidizing and reducing agents in redox reactions

Steps:

• Determine oxidation states: Cu decreases from +2 in CuO to 0 in Cu (reduction); C increases from 0 to +4 in CO₂ (oxidation).
• Identify the reducing agent as the species that is oxidized (loses electrons): carbon.
• Identify the oxidizing agent as the species that is reduced (gains electrons): CuO.
• Confirm the reaction is redox based on electron transfer.

Why B is correct:

• Carbon is oxidized (0 to +4), so it donates electrons to reduce Cu²⁺, acting as the reducing agent per the definition in redox chemistry.

Why the others are wrong:

• A: Carbon is oxidized, so it reduces others; the oxidizing agent would be CuO.
• C: CuO undergoes reduction (Cu²⁺ gains electrons), not oxidation.
• D: CuO is reduced, so it oxidizes carbon; it is the oxidizing agent.

Final answer: B