Through this kit we want to demonstrate the electrolysis process of a molten salt and, in particular, show how electrolysis can take place only if the salt is melted. We prepare an electrical circuit between a D.C. generator, a light bulb and two graphite electrodes. Taking the lead bromide and immersing the tips of the electrodes in it, the bulb does not light up as it is a crystalline ionic substance. If a Bunsen burner is lit under the salt melting it, when the salt reaches its melting point the bulb lights up to indicate the closing of the circuit and the start of the electrolytic process. The lead bromide used for the experiment is produced by precipitation by making the the potassium bromide react with the lead nitrate.
THEORETICAL – EXPERIMENTAL HANDBOOK