Question Detail
Question
The standard reduction potentials are: Cu²⁺ + 2e⁻ → Cu, E° = +0.34 V; Ag⁺ + e⁻ → Ag, E° = +0.80 V. The EMF of the cell reaction: Cu + 2Ag⁺ → Cu²⁺ + 2Ag is?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Oxidation: Cu → Cu²⁺ + 2e⁻, E°_ox = -0.34 V (or +0.34 V for reduction, so oxidation potential is -0.34 V relative to SHE; but better: E°cell = E°cathode - E°anode = 0.80 - 0.34 = 0.46 V). The cathode is Ag⁺/Ag, the anode is Cu²⁺/Cu.
Hint
EMF = E°(reduction at cathode) - E°(reduction at anode). Identify which half-reaction occurs at each electrode.