A molten ionic compound splits into a metal and a non-metal

1. Heating an ionic compound until it is molten frees its ions so it can be electrolysed.
2. The metal forms at the cathode and the non-metal forms at the anode.
3. A simple binary compound gives just these two elements.

Molten lead bromide gives lead and bromine

1. Molten lead bromide, ${PbBr}_2$, contains ${Pb}^{2+}$ ions and ${Br}^{-}$ ions.
2. At the cathode, lead ions are reduced to a bead of molten lead.
   1. $${Pb}^{2+}+2e^{-}\to Pb$$
3. At the anode, bromide ions are oxidised to orange-brown bromine vapour.
   1. $$2{Br}^{-}\to {Br}_2+2e^{-}$$

Predicting the products of any molten compound

1. Identify the metal ion and the non-metal ion in the compound.
2. Send the metal to the cathode and the non-metal to the anode.
3. For example, molten sodium chloride gives sodium at the cathode and chlorine at the anode.
4. Write a half equation for each electrode to show the electron transfer.