Free Energy Changes and Cell Emf’s


Free Energy Changes and Cell Emf’s


The reversible cell e.m.f. (Ecell) is related to the free energy change G by the equation
G = -nFE
Or  G0 = -nFE0
where n is the number of electrons involved in the reaction F is the Faraday constant and E is thereversible e.m.f of the cell.

If Ecell>0 and hence G<0, cell reaction is spontaneous in the given direction and vice versa. If Ecell=0 and hence G= 0, then cell is in a state of equilibrium.

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