CHEMISTRY 5070 · STRUCTURED PRACTICE
1
Molten lead(II) bromide, , is electrolysed using graphite electrodes connected to a 6 V d.c. power supply.
(a)
[2]Define the term electrolysis and state why lead(II) bromide must be molten rather than solid for electrolysis to occur.
(b)
[2]Describe the visual observations made at the anode (+) and at the cathode (-) during electrolysis.
(c)
[2]Construct the ionic half-equation for the reaction taking place at the anode and state whether oxidation or reduction occurs.
(d)
[2]Explain, in terms of particle movement, how electric current is conducted through
(i)
the graphite electrodes and
(ii)
[2]the molten electrolyte.
Total: 8 marks