Faraday concluded after several experiments on electric current in a non-spontaneous process that the mass of the products yielded on the electrodes was proportional to the value of current supplied to the cell, the length of time the current existed, and the molar mass of the substance analyzed. In other words, the amount of a substance deposited on each electrode of an electrolytic cell is directly proportional to the quantity of electricity passed through the cell.
Below is a simplified equation of Faraday's first law:
where
:m is the mass of the substance produced at the electrode (in grams),
:Q is the total electric charge that passed through the solution (in coulombs),
:n is the valence number of the substance as an ion in solution (electrons per ion),
:M is the molar mass of the substance (in grams per mole).