CAIE A Level Chemistry 9701 · Electrochemistry
A student electrolyses molten lead(II) bromide, , using inert carbon electrodes. During the electrolysis, a dark grey metal forms at the cathode and a red-brown gas is released at the anode.
Describe, in terms of the ions present and the redox reactions at each electrode, what happens during this electrolysis. Include the electrode reactions in your answer.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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