The Electrochemical Potential is a measurement of the energy stored in the chemical potential of redox reactions. The Electrochemical Potential can be calculated by adding up the electrode potentials of each half-cell. These individual half-cell potentials can be calculated by standardizing its reducing or oxidizing potential to the standard hydrogen electrode (SHE). The difference in electrode voltage with the SHE gives a predictive value of the half-cell potential.
However, before one can start to calculate the Electrochemical Potential, one must first manipulate the half-cell reactions to make sure that the right cell is either undergoing reduction or oxidation. The half-cell with the smallest potential and integer sign must be reversed to create an overall positive cell potential. Consider the following redox reaction:
Cu2+(aq) + Zn(s) --> Cu(s) + Zn2+
Cu2+(aq) + 2e- --> Cu(s)
E = 0.34 V
Zn(s) --> Zn2+(aq) + 2e-
E = 0.76 V
It can be seen that the reduction potential of Cu2+ is 0.34V and the oxidizing potential of Zn is 0.76. Adding the two values together gives a total electrochemical potential of 1.10 V. Thus, it is can be seen that understanding electrochemical potentials in the context of electrochemical cells is important for the study of electrochemistry.
Title Image Credit: Wikimedia Commons© BrainMass Inc. brainmass.com June 20, 2018, 1:34 pm ad1c9bdddf