Given the standard reduction potentials at 25 degrees C, what is the standard cell potential of a Ni (s) | Ni2+ (aq) || Ag+ (aq) | Ag (s) galvanic cell?

Given the standard reduction potentials at 25 degrees C, what is the standard cell potential of a Ni (s) | Ni2+ (aq) || Ag+ (aq) | Ag (s) galvanic cell?

• A. 0.56 V
• B. 1.02 V
• C. 1.35 V
• D. 1.81 V

Answer: (A)

In a galvanic cell, the standard cell potential is found by taking the difference between the cathode’s reduction potential and the anode’s reduction potential: E°cell = E°cathode − E°anode. The Ag+/Ag couple has a higher tendency to be reduced (E° ≈ +0.80 V) than Ni2+/Ni (E° ≈ −0.23 V), so silver is reduced at the cathode and nickel is oxidized at the anode. Balancing electrons gives Ni(s) → Ni2+(aq) + 2 e− and 2 Ag+(aq) + 2 e− → 2 Ag(s). Therefore E°cell = +0.80 − (−0.23) ≈ 1.03 V, which rounds to about 1.02 V. So the standard cell potential is approximately 1.02 V.

In a galvanic cell, the standard cell potential is found by taking the difference between the cathode’s reduction potential and the anode’s reduction potential: E°cell = E°cathode − E°anode. The Ag+/Ag couple has a higher tendency to be reduced (E° ≈ +0.80 V) than Ni2+/Ni (E° ≈ −0.23 V), so silver is reduced at the cathode and nickel is oxidized at the anode. Balancing electrons gives Ni(s) → Ni2+(aq) + 2 e− and 2 Ag+(aq) + 2 e− → 2 Ag(s). Therefore E°cell = +0.80 − (−0.23) ≈ 1.03 V, which rounds to about 1.02 V. So the standard cell potential is approximately 1.02 V.