Which of the following statements about the cell notation Mg/Mg$^{2+}$//Cu$^{2+}$/Cu is correct?

Step 1: Analyze the question We need to read the cell notation correctly. In the standard convention, the left side is the anode (oxidation) and the right side is the cathode (reduction). The double line (//) represents the salt bridge (or porous partition), not the electrodes.

Step 2: Read the notation Mg / Mg²⁺ // Cu²⁺ / Cu

• Left: Mg → Mg²⁺ + 2e⁻ (oxidation, so Mg is the anode)
• Right: Cu²⁺ + 2e⁻ → Cu (reduction, so Cu is the cathode)

Magnesium is higher in the electrochemical series (E° = -2.37 V) than copper (E° = +0.34 V), so it loses electrons more readily. This agrees with the notation.

Overall: Mg + Cu²⁺ → Mg²⁺ + Cu E°cell = +0.34 - (-2.37) = +2.71 V

Step 3: Test each option

• A. Copper is the anode: wrong. Copper is the cathode.
• B. Magnesium is reduced: wrong. Magnesium is oxidized.
• C. Magnesium is the anode: correct. Oxidation occurs at Mg.
• D. The double line represents the electrodes: wrong. It represents the salt bridge.

Answer: C. Magnesium is the anode

Tip: Remember "AN OX and RED CAT": Anode = Oxidation, Reduction = Cathode. Also, in cell notation, the anode is written on the left and the cathode on the right, and the // is always the salt bridge.