Which of the following half-reactions correctly describes an oxidation process?

• A. Ag^{+} + e^{-} ightarrow Ag
• B. Cl_{2} + 2e^{-} ightarrow 2Cl^{-}
• C. Cu^{2+} + 2e^{-} ightarrow Cu
• D. Fe^{2+} ightarrow Fe^{3+} + e^{-}

Answer: (D)

Verified step by step guidance

1. Recall that oxidation is the process where a species loses electrons, and reduction is the process where a species gains electrons.
2. Examine each half-reaction to identify whether electrons are on the reactant side (indicating reduction) or on the product side (indicating oxidation).
3. For the half-reaction \(Ag^{+} + e^{-} \rightarrow Ag\), electrons are gained, so this is a reduction process.
4. For the half-reaction \(Cl_{2} + 2e^{-} \rightarrow 2Cl^{-}\), electrons are gained, so this is also a reduction process.
5. For the half-reaction \(Fe^{2+} \rightarrow Fe^{3+} + e^{-}\), electrons are lost (on the product side), indicating this is an oxidation process.