A-LevelChemistryElectrochemistry9701/12 · Oct/Nov 2015 · Q71 Mark

The process of electrolysis can be used to purify copper, and to extract aluminium from an aluminium oxide/cryolite mixture. What are the reactions at the anode in each of these processes?

Apurification of copper: Cu2+ + 2e → Cu, extraction of aluminium: 2O2- → O2 + 4e-

Bpurification of copper: Cu2+ + 2e – Cu, extraction of aluminium: 4OH- → O2 + 2H2O + 4e¯

Cpurification of copper: Cu → Cu2+ + 2e-, extraction of aluminium: 2O2- → O2 + 4e-

Dpurification of copper: Cu → Cu2+ + 2e¯, extraction of aluminium: 4OH- → O2 + 2H2O + 4e¯

✓ Correct answer

C: purification of copper: Cu → Cu2+ + 2e-, extraction of aluminium: 2O2- → O2 + 4e-

Oracle Prep sorts past-paper questions by topic, so you can drill Electrochemistry and see which topics are most likely to come up next.

Topic: Electrochemistry, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Oct/Nov 2015 Paper 1 Variant 2, question 7.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content