Figure above shows the apparatus set up for electrolysis of molten lead (II) bromide.
The electrolysis process start when lean (II) bromide start melting.
At the Cathode | At the Anode |
Ion presence: Pb2+ | Ion presence: Br– |
Observation When electricity is flowing, a silvery deposit of lead metal forms on the cathode. In fact, as it is molten, it is more likely to drip off in a molten blob. | Observation When electricity is flowing, brown fumes of bromine gas are seen at the anode. |
Half equation Pb2+ + 2e —> Pb | Half equation 2Br– —> Br2 + e |
Summary: PbBr2 —> Pb + Br2 |