Calculate the standard cell emf for the following cell: Mg

Question

Calculate the standard cell emf for the following cell: Mg | Mg²⁺ || NO₃^- (acid soln)| NO(g) | Pt

Quizplus · Accepted Answer

The correct answer is A because the standard cell emf for the given cell is 3.33 V. This can be calculated using the standard reduction potentials of the half-reactions:Mg²⁺ + 2 e^- → Mg(s) E° = -2.37 VNO₃^- + 4 H⁺ + 3 e^- → NO(g) + 2 H₂O E° = +0.96 VThe overall cell reaction is:Mg(s) + 2 NO₃^- + 4 H⁺ → Mg²⁺ + 2 NO(g) + 2 H₂OThe standard cell emf is:E° = E°_cathode - E°_anode = +0.96 V - (-2.37 V) = +3.33 V