Calculate the standard cell potential for the following reaction: Mg (s) + Cu²⁺ (aq) → Cu (s) + Mg²⁺ (aq). Given the standard reduction potentials: Cu²⁺ (aq) + 2 e⁻ → Cu (s) is 0.34 V and Mg²⁺ (aq) + 2 e⁻ → Mg (s) is -2.37 V.

• A. 1.34
• B. 2.03
• C. 1.97
• D. 2.71

Answer: (D)

Verified step by step guidance

1. Identify the half-reactions involved in the overall reaction. The given reaction is: Mg (s) + Cu²⁺ (aq) → Cu (s) + Mg²⁺ (aq). The half-reactions are: Cu²⁺ (aq) + 2 e⁻ → Cu (s) and Mg (s) → Mg²⁺ (aq) + 2 e⁻.
2. Determine the standard reduction potentials for each half-reaction. From the problem, the standard reduction potential for Cu²⁺ (aq) + 2 e⁻ → Cu (s) is 0.34 V, and for Mg²⁺ (aq) + 2 e⁻ → Mg (s) is -2.37 V.
3. Identify which half-reaction is the oxidation and which is the reduction. In the given reaction, Mg is oxidized to Mg²⁺, and Cu²⁺ is reduced to Cu.
4. Calculate the standard cell potential (E°cell) using the formula: E°cell = E°cathode - E°anode. Here, the cathode is where reduction occurs (Cu²⁺ to Cu), and the anode is where oxidation occurs (Mg to Mg²⁺).
5. Substitute the standard reduction potentials into the formula: E°cell = 0.34 V - (-2.37 V). Simplify the expression to find the standard cell potential.