A-LevelChemistryElectrochemistryMay/June 2013Paper 1 Q11 Mark
During the electrolysis of molten aluminium oxide to produce aluminium, using carbon electrodes, two consecutive reactions occur at the anode, each producing a different gas. How does the oxidation number of oxygen change in these reactions?
Adecreases by 2, then increases by 2
Bincreases by 2, then decreases by 2
Cincreases by 2, then decreases by 4
Dno change, then decreases by 2
✓ Correct Answer
The correct answer is B. This question tests the candidate's understanding of electrochemistry within the Chemistrysyllabus. The examiner's mark scheme requires...
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
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