In a redox reaction, an oxidising agent is which of the following?

• A. Something that gets oxidised
• B. Something that gets reduced
• C. Gains electrons
• D. Loses oxygen

Answer: (B)

In redox chemistry, oxidation is the loss of electrons and reduction is the gain of electrons. The oxidising agent is the substance that causes another substance to be oxidised by taking electrons from it. In doing so, the oxidising agent itself gains electrons and becomes reduced. So the best description is that the oxidising agent is something that gets reduced.

This highlights the role: it drives the oxidation of another species while it itself undergoes reduction. Losing oxygen isn’t the defining feature of an oxidising agent, since redox is about electron transfer, not just oxygen transfer.