ACS Chemistry Practice Exam 2026 – The All-in-One Guide to Exam Success!

In a redox (reduction-oxidation) reaction, an oxidizing agent is the species that causes another substance to be oxidized, which means it facilitates the loss of electrons from that substance. When the oxidizing agent interacts with the substance undergoing oxidation, it gains electrons itself in the process. This is why the role of the oxidizing agent is characterized by the gaining of electrons.

For example, in the reaction between zinc and copper(II) sulfate, zinc is oxidized as it loses electrons, while copper(II) ions are reduced as they gain those electrons, and copper(II) sulfate acts as the oxidizing agent in this case. As a result, the electron transfer that occurs in redox reactions is fundamental, with the oxidizing agent being specifically defined by its ability to accept electrons and drive the oxidation process.

In summary, the role of an oxidizing agent is crucial as it not only promotes the oxidation of another substance by gaining electrons but is also reduced in the process, which aligns with the definition and function of an oxidizer in redox chemistry.