A student electrolyses copper(II) sulfate solution, CuSO₄(aq), using inert graphite electrodes.
Name the product at each electrode.
Write the half equation for the reaction at the cathode.
Sulfate ions are attracted to the anode.
Explain why the product at the anode is not made from the sulfate ions, and describe how it is made instead.
Write the half equation for the reaction at the anode.
The student continues the electrolysis for a long time. The blue colour of the solution fades and the pH of the solution decreases.
Explain these observations.
The student repeats the experiment using copper electrodes instead of graphite electrodes.
Describe how the observations at the anode are different.
52 exam-style questions on OCR GCSE Chemistry 3.4 Electrolysis, covering 3.4.1 Products formed at the electrodes in electrolysis and 3.4.2 The technique of electrolysis. Each one has a worked solution and a mark scheme showing where the marks go.