What does a negative cell potential indicate in a galvanic cell?

In a galvanic cell, the cell potential (often represented as E°) is a measure of the voltage generated by the cell under standard conditions. A negative cell potential indicates that the electrochemical reaction occurring in the galvanic cell is not favorable for spontaneous occurrence. In other words, when a galvanic cell has a negative cell potential, it means that the reactions that would normally produce an electric current are not energetically viable without external energy input.

The correct interpretation of a negative cell potential is that the reaction cannot occur spontaneously. This means that if left to its own devices, the reaction would not proceed to produce electrical work. In a typical galvanic cell scenario, where spontaneous reactions are harnessed to produce electricity, a negative cell potential signifies that the reverse of the desired reaction (which would produce energy) would be favored instead. Thus, the system would require an input of energy to drive the reaction in the forward direction.

This understanding is critical in electrochemistry, especially when analyzing energy relationships in redox reactions within galvanic and electrolytic cells. In an electrolytic cell, for example, a negative potential typically indicates that external energy must be supplied to overcome the energy barrier of the desired chemical transformation.

Recognizing this principle helps in