10.2.2: Electrolytic cells
E-assessement - B1: Periodic Table:
Activity - Class demonstration
Discussion of redox reactions, reversing the potential and electrolysis.
Demonstration of the electrolysis of molten lead(II) bromide.
PbBr2(l) Pb(l) + Br2(g)
Note: This must be carried out in the fume hood in a clean nickel crucible. It should be possible to melt the lead(II) bromide first in a nickel crucible and then attach the negative terminal of the power supply to the nickel crucible itself and then lower a graphite rod connected to the positive terminal directly down into the molten salt.
This can then be linked to the extraction of the group 1 and 2 metals.
The students can set up an cell to examine the products when copper(II) chloride solution is electrolysed.
Include a voltmeter across the electrodes to monitor the potential used.