Which statement best describes the role of the oxidising agent?

• A. It is reduced (gains electrons).
• B. It increases the oxidation number of another atom.
• C. It donates electrons to the other reactant.
• D. It remains unchanged in oxidation state.

Answer: (A)

In redox processes, one species is oxidized (loses electrons) and another is reduced (gains electrons). The oxidising agent is the species that accepts electrons from the one being oxidized, so it itself is reduced. That’s why the statement that describes it as gaining electrons is the best description. The other reactant’s oxidation number increases as it loses electrons, but the crucial role of the oxidising agent is to take those electrons, not to donate them. Donating electrons would describe a reducing agent, and the oxidising agent does not stay unchanged in oxidation state—it undergoes reduction by gaining electrons.