A voltaic cell consisting of cadmium and silver electrodes Note that the anode is the electrode where the oxidation occurs, while the cathode is the electrode where reduction takes place. The identification of the anode and cathode in an electrolytic cell is the same. To explain the functioning of electrochemical cells, work is needed to move electrons in a wire and to move ions through a solution to an electrode. To accomplish this an electric charge moves from a point of high electric potential to a point of low electric potential. Also, the work needed to move an electric charge though a conductor depends on the total charge moved and the potential difference.
Potential difference is the difference in the electric potential between two points.
The Faraday constant is the charge on one mole of electrons and is equal to 96,485 coulombs. In moving one Faraday of charge from one electrode to another, the work done by an electrochemical cell is the product of the Faraday constant times the potential difference between the electrodes. The maximum potential difference between the electrodes of a voltaic cell is called the electromotive force of the cell, which is denoted as E cell . To measure the potentials of electrodes, a standard hydrogen electrode is needed. This gives a great advantages in tabulating cell emf's.