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Electrochemistry

Question
CBSEENCH12005955

Show that the electrical work obtainable from a galvanic cell is given by the expression.
G° = -nFE°cell

Solution
The cell potential is simply related to the free energy change for the reaction. In an electro chemical cell the system does work by transferring the electric charge through an external circuit. The free energy change G is equal to electrical work done.

G = Welectrical

For reaction occurring in a electrochemical cell whose electrodes differ in potential by Ecell, the work done when amount of charge nF is transferred is given by
                   Welect = -nFEcell
∴                   G = -nFEcell
Under standard state conditions
ΔG° = – n FE°cell.