What is the relationship between Gibbs free energy of the cell reaction in a galvanic cell and the emf of the cell? When will the maximum work be obtained from a galvanic cell?
• The relationship between Gibbs free energy of the cell reaction in a galvanic cell and the emf of the cell:
ΔrGcell = -nFEcell
Where, ΔrGcell = Gibbs free energy of the reaction.
F= Faraday constant
Ecell = Emf of the cell
n= Number of moles of electron transferred in the radox reaction.
• At standard condition,
When, concentration of all reacting species is unity, T= 298 K
Ecell = 
Or, ΔG° = -nF
• The maximum work can be obtained from a galvanic cell when the charge is passed reversibly.
• The reversible work done by the galvanic cell is written as,
ΔrGcell = -nFEcell
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