Paper 2 · Electrolysis and electroplating
Aqueous copper(II) sulfate is electrolysed using copper electrodes. What happens at the anode?
ACu2+ ions are reduced to copper atoms (Cu2+ + 2e- -> Cu).
BWater molecules are oxidised to oxygen gas.
CHydroxide ions are reduced to hydrogen gas.
DCopper atoms are oxidised to Cu2+ ions (Cu -> Cu2+ + 2e-).
Explanation: At the anode, copper metal is oxidised into solution: Cu -> Cu2+ + 2e-; this is the basis of copper electroplating/refining.
Derived from ZIMSEC Chemistry 5071/2 Paper 2 Theory, November 2013, Q4
