Industrial production of magnesium relies on the Dow process, where magnesium chloride is electrolysed in its molten form.
The electrolysis is carried out in a cell where the cathode (negative electrode) is made of steel, and the anode (positive electrode) is made of graphite.
Liquid magnesium is collected at the negative electrode, while chlorine gas bubbles off at the positive electrode.
Explain why magnesium chloride must be melted before it can be electrolysed.
Write an ionic half-equation to represent the formation of magnesium at the negative electrode.
Suggest why steel is not used for the positive electrode.
