Chemistry 0620 · Question 1[8 marks]
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.