Which term refers to chemical equations that show oxidation and reduction separately and can be combined to yield the overall redox equation?

• A. Full Reactions
• B. Redox Equations
• C. Half-reactions
• D. Electrochemical Cells

Answer: (C)

Oxidation and reduction are analyzed by writing two separate equations called half-reactions. They show where electrons are released in oxidation and where they are gained in reduction. Since electrons must be conserved, the number of electrons in both halves is the same; balance each half for atoms and charge, usually by adding H+, H2O, or OH− as needed depending on the medium. Once both halves are balanced, add them together and cancel the electrons to obtain the overall redox equation. This separation and subsequent recombination is the standard way to analyze redox processes, making it clear which species are oxidized and reduced and ensuring the equation is balanced. For example, in an acidic solution, oxidizing Fe2+ to Fe3+ gives Fe2+ → Fe3+ + e−, while reducing MnO4− to Mn2+ in acidic solution gives MnO4− + 8 H+ + 5 e− → Mn2+ + 4 H2O. To balance, multiply the oxidation half by 5 so electrons match, then add to the reduction half, cancelling the electrons to yield the overall equation. The term that refers to these separate oxidation and reduction pieces is half-reactions. Full reactions describe the complete transformation without showing the split; redox equations refer to the overall electron transfer, while electrochemical cells are devices that harness or drive such reactions.