Reducing/oxidizing agents

The species that gains electrons is reduced and acts as the oxidizing agent (or oxidant). (In short, reduced = oxidizing agent.)... 

The substance oxidized (reducing agent) is O2- because it is the reactant that lost electrons. The substance reduced (oxidizing agent) is H1+ because it is the reactant that gained electrons. 

Recognize oxidation-reduction reactions and identify which species are oxidized, reduced, oxidizing agents, and reducing agents... 

The reduction half-reaction occurs at the cathode. Electrons are gained by the substance being reduced (oxidizing agent) and enter the cell at the cathode. 

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