The standard electrode potential for any electrode
dipping in an appropriate solution is defined with respect to standard electrode
potential of hydrogen electrode taken as zero The standard potential of the cell
can be obtained by taking the difference of the standard potentials of cathode and
anode (
(
)
o
Ecell
 = Eocathode – Eoanode) The standard potential of the cells are
related to standard Gibbs energy (DrGo = –nF
(
)
o
Ecell
) and equilibrium constant
(DrGo = – RT ln K) of the reaction taking place in the cell Concentration dependence
of the potentials of the  electrodes and the cells are given by Nernst equation