Electrolysis of concentrated aqueous sodium chloride (brine)

-The electrolyte in this reaction is a solution of NaCl and H₂O. This will become hydrogen (2H+), chloride (2Cl-), hydroxide and sodium ions. -The chloride will move towards the anode since it is a positive ion where it will lose electrons to form chlorine gas. Half equation for the reaction at the anode: -2Cl- -> Cl₂ + 2e- (oxidation) -However, at the cathode sodium is not formed but hydrogen is formed. This is because the sodium is more reactive than hydrogen (explained further below). Half equation for the reaction at the anode: -2H+ +2e- -> H₂ (reduction) -In this electrolysis, sodium hydroxide is left behind which is useful just like the rest of the substances made. This electrolysis is done at a large scale with sea water to make these products for industrial use.