Which of the following is an oxidation half-reaction?A.Fe2+ Fe3+ + e-B.Fe3+ + e- Fe2+C.Fe + 2e- Fe2+D.Fe(s) Fe(l)

Break Down the Problem

1. Identify the half-reaction types: an oxidation half-reaction involves the loss of electrons.
2. Review each option to determine if it represents an oxidation process.

Relevant Concepts

• Oxidation is defined as the process where an element loses electrons, resulting in an increase in oxidation state.
• A half-reaction can either involve oxidation or reduction:
  • Oxidation Half-Reaction: $\text{A} \rightarrow \text{B} + e^-$
  • Reduction Half-Reaction: $\text{B} + e^- \rightarrow \text{A}$

Analysis and Detail

1. Option A: $\text{Fe}^{2+} \rightarrow \text{Fe}^{3+} + e^-$

   • This reaction shows iron (Fe) losing an electron to form $\text{Fe}^{3+}$, indicating oxidation.

2. Option B: $\text{Fe}^{3+} + e^- \rightarrow \text{Fe}^{2+}$

   • This reaction shows iron gaining an electron which indicates reduction.

3. Option C: $\text{Fe} \rightarrow \text{Fe}^{2+} + 2e^-$

   • This reaction shows solid iron losing two electrons to form $\text{Fe}^{2+}$, indicating oxidation.

4. Option D: $\text{Fe(s)} \rightarrow \text{Fe(l)}$

   • This reaction involves a phase change but does not mention any electron transfer, so it is not a half-reaction.

Verify and Summarize

• Oxidation is characterized by the loss of electrons.
• Options A and C are both oxidation half-reactions. Though, A is generally the more straightforward common representation of an electron transfer in oxidation.

Final Answer

Answer: The oxidation half-reaction is A. $\text{Fe}^{2+} \rightarrow \text{Fe}^{3+} + e^-$.