Which statement best describes an oxidizing agent?

• A. the species that donates electrons
• B. the species that gets reduced
• C. the species that increases its oxidation state
• D. the species that decomposes

Answer: (B)

In redox chemistry, the oxidizing agent is the species that accepts electrons from another and is reduced in the process. Because it takes electrons from the other substance, it drives oxidation of that substance and itself becomes reduced. That’s why describing the oxidizing agent as the species that gets reduced is the best fit. For example, in a reaction where permanganate in acidic solution gains electrons to become Mn2+, permanganate is the oxidizing agent because it accepts electrons and is reduced, while the other substance is oxidized.

The idea of donating electrons corresponds to the reducing agent—the one that is oxidized. Saying a substance increases its oxidation state describes the one being oxidized, not the one causing the oxidation. Decomposition doesn’t specify any redox role, so it isn’t a defining characteristic of an oxidizing agent.