Electrochemistry

When reacting components are charged or involve electron transfer, additional terms must be added to the chemical potential to represent the extra energy of a charged species in an electrostatic potential. The sum of the chemical potential and the electrostatic potential defines the ``electrochemical potential.'' At equilibrium, the electrochemical potentials are equal between phases. The electrochemical potential yields the Nernst equation. The Nernst equation is exactly the same as an equilibrium constant equation, except with the energy of charged species being added in.