Which of the following is an oxidation half-reaction?

• A. 2H^{+} + 2e^{-} → H_2
• B. Cl_2 + 2e^{-} → 2Cl^{-}
• C. Fe → Fe^{2+} + 2e^{-}
• D. Cu^{2+} + 2e^{-} → Cu

Answer: (C)

Verified step by step guidance

1. Understand that an oxidation half-reaction involves the loss of electrons, meaning electrons appear as products in the equation.
2. Look at each given half-reaction and identify whether electrons are on the reactant side (reduction) or product side (oxidation).
3. For example, in the reaction \$2H^{+} + 2e^{-} \rightarrow H_2$, electrons are on the reactant side, so this is a reduction half-reaction.
4. In the reaction \(Fe \rightarrow Fe^{2+} + 2e^{-}\), electrons are produced on the product side, indicating that iron is losing electrons and this is an oxidation half-reaction.
5. Confirm that the correct oxidation half-reaction is the one where the species loses electrons, which matches the form \(Fe \rightarrow Fe^{2+} + 2e^{-}\).