Oxidizing agent is the substance being reduced.

• A. The substance being oxidized
• B. The electron donor
• C. The substance being reduced
• D. The oxidizing agent

Answer: (C)

In redox reactions, oxidation is the loss of electrons and reduction is the gain of electrons. The substance that drives the oxidation by accepting electrons is the oxidizing agent. Because it accepts electrons, that substance itself undergoes reduction. So the oxidizing agent is the species that gets reduced.

Think of it this way: the electron donor gives away electrons and becomes oxidized, while the electron acceptor takes those electrons and becomes reduced. Therefore, saying the oxidizing agent is the substance being reduced is correct, since it is the electron acceptor in the reaction.