A recycling plant has an aqueous solution that contains either silver ions or magnesium ions. The solution is electrolysed using inert electrodes.
The order of reactivity is shown, starting with the most reactive:
magnesium, hydrogen, silver
Which observation at the cathode would show that the solution contains magnesium ions?
Bubbles of hydrogen gas form.
Bubbles of oxygen gas form.
No change is seen at the cathode.
A coating of magnesium forms.
98 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.