Given the standard electrode reduction potentials: Zn^{2+} + 2e^- ightarrow Zn ext{ } E^ext{0} = -0.76 ext{ V} and Cu^{2+} + 2e^- ightarrow Cu ext{ } E^ext{0} = +0.34 ext{ V}, which metal will be oxidized when a zinc electrode and a copper electrode are connected in a voltaic cell?

• A. Both zinc and copper
• B. Zinc
• C. Neither zinc nor copper
• D. Copper

Answer: (B)

Verified step by step guidance

1. Identify the given standard reduction potentials: for Zn^{2+} + 2e^- \rightarrow Zn, E^{0} = -0.76 V; for Cu^{2+} + 2e^- \rightarrow Cu, E^{0} = +0.34 V.
2. Recall that in a voltaic (galvanic) cell, the species with the higher (more positive) reduction potential will be reduced (gain electrons), and the species with the lower (more negative) reduction potential will be oxidized (lose electrons).
3. Compare the two potentials: copper has a higher reduction potential (+0.34 V) than zinc (-0.76 V), so copper ions tend to gain electrons and be reduced.
4. Since zinc has the lower reduction potential, zinc metal will lose electrons and be oxidized to Zn^{2+} ions in the cell.
5. Therefore, the zinc electrode acts as the anode (oxidation site), and the copper electrode acts as the cathode (reduction site) in the voltaic cell.