Which of the following represents an oxidation half-reaction?

• A. Ag^{+} + e^{-} → Ag
• B. Cu^{2+} + 2e^{-} → Cu
• C. Fe → Fe^{2+} + 2e^{-}
• D. Cl_{2} + 2e^{-} → 2Cl^{-}

Answer: (C)

Verified step by step guidance

1. Understand that an oxidation half-reaction involves the loss of electrons, meaning the species on the reactant side loses electrons to form the product.
2. Look at each given half-reaction and identify whether electrons are on the reactant side (indicating reduction) or on the product side (indicating oxidation).
3. For example, in the half-reaction \(Ag^{+} + e^{-} \rightarrow Ag\), electrons are gained, so this is a reduction half-reaction.
4. In the half-reaction \(Fe \rightarrow Fe^{2+} + 2e^{-}\), electrons are produced on the product side, indicating that iron is losing electrons, which is oxidation.
5. Therefore, the half-reaction that shows electrons as products represents oxidation, which matches \(Fe \rightarrow Fe^{2+} + 2e^{-}\).