The dotted line represents a membrane to keep the components separated. At the anode a yellow-green gas is formed, and at the cathode a silvery metal is formed. In the electrolysis of a molten salt, the possible half-reactions are usually limited to those involving ions from the salt. This is a less expensive, more convenient procedure. At the other electrode, there is also a complication.
Water is easier to oxidize than sulfate ion.
Faraday discovered that the quantity of a substance undergoing chemical change at each electrode is proportional to the quantity of electricity which passes through the cell. The quantity of electricity can be expressed in the number of electrons, Faradays, or Coulombs. First write the reaction.