Thursday, 24 November 2016

Electrolysis of a molten salt

I worked in a fume cupboard to attempt the electrolysis of molten lead bromide. This photograph was taken through the glass window. It started out as a white powder and took a long time to melt. You can see that there is an orange gas in the beaker. This shows that bromine gas has been produced. It is a toxic gas - hence the fume cupboard. Bromide is a negative ion so is attracted to the anode. The lead is a positive ion and so is attracted to the cathode. The lead was hot when the electrodes were extracted from the beaker and soon turned from grey to yellow. I'm guessing that in the heat it had oxidised and the yellow was lead oxide. When it was all safe, I photographed the end:
The cathode was the right hand one. Perhaps that's a rim of lead.