Galvanic Cell: Determining E°

How can we determine E° for a galvanic cell?

What is the relationship between E°, ∆G°, and n in a galvanic cell?

Answer:

To determine E° for a galvanic cell, we can use the formula E° = ∆G° / -nF, where E° is the standard electromotive force, ∆G° is the standard Gibbs free energy change, n is the number of moles of electrons transferred in the reaction, and F is the Faraday constant.

In a galvanic cell, the electromotive force (E°) is directly related to the standard Gibbs free energy change (∆G°) and the number of moles of electrons transferred in the reaction (n). The formula E° = ∆G° / -nF can be used to calculate the standard electromotive force of the cell.

When the standard Gibbs free energy change (∆G°) is given as -6.3 kJ/mol and the number of moles of electrons transferred (n) is 3, we can plug these values into the formula to find the standard electromotive force (E°).

Using the formula E° = ∆G° / -nF and substituting the values -6.3 kJ/mol for ∆G°, 3 for n, and 96,500 J/(V･mol) for F, we get:

E° = -6.3 / -3 * 96500 = 0.000217 V

Therefore, the E° for the galvanic cell is 0.000217 volts.