Which of the following changes represents an oxidation process?

• A. O_2 + 4e^{-} + 4H^{+} ightarrow 2H_2O
• B. Fe^{2+} ightarrow Fe^{3+} + e^{-}
• C. Cl_2 + 2e^{-} ightarrow 2Cl^{-}
• D. Cu^{2+} + 2e^{-} ightarrow Cu

Answer: (B)

Verified step by step guidance

1. Understand that oxidation is the loss of electrons, while reduction is the gain of electrons. In a redox reaction, oxidation and reduction occur simultaneously.
2. Examine each given half-reaction to identify whether electrons are lost or gained:
3. For \(O_2 + 4e^{-} + 4H^{+} \rightarrow 2H_2O\), electrons are on the reactant side, indicating a gain of electrons, so this is a reduction process.
4. For \(Fe^{2+} \rightarrow Fe^{3+} + e^{-}\), electrons are on the product side, indicating a loss of electrons, so this is an oxidation process.
5. For \(Cl_2 + 2e^{-} \rightarrow 2Cl^{-}\) and \(Cu^{2+} + 2e^{-} \rightarrow Cu\), electrons are gained on the reactant side, indicating reduction processes.