Which statement correctly describes the spontaneity criterion for a galvanic cell?

• A. E°cell > 0
• B. E°cell < 0
• C. E°cathode < E°anode
• D. E°cathode > 0

Answer: (A)

Spontaneity in a galvanic cell is determined by the sign of the standard cell potential. If E°cell is positive, the reaction can proceed on its own, releasing free energy (ΔG° = -nF E°cell < 0). The cell potential is the difference between the cathode and anode reduction potentials: E°cell = E°cathode - E°anode. When the cathode has the higher reduction potential, this difference is positive, so electrons flow spontaneously from the anode to the cathode. Therefore, E°cell > 0 is the correct criterion for spontaneity.

If E°cell were negative, the reaction would not be spontaneous in a galvanic cell. The idea that the cathode’s potential must simply be greater than zero isn’t the requirement—what matters is that the difference between cathode and anode potentials is positive, which can occur even if both potentials are negative, as long as the cathode’s is less negative than the anode’s.