9701 MCQ Solution 33

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Question 33: [Physical > Electrochemistry]:
Which statements about the commercial extraction of aluminium are correct?

1 The cathode reaction is Al3+ + 3e- à Al.
2 The lining of the electrolytic cell acts as the cathode.
3 The electrolyte is purified Al2O3 in Na3AlF6.
Reference: Past Exam Paper – November 2002 Paper 1 Q33



Solution 33:
Answer: A.

In the extraction of aluminium the electrolyte is molten aluminium oxide. The cathode is negatively charged, attracts the Al3+ ions and reduce them to Al atoms, thus 1 is correct. 2 is a fact. 
Na3AlF6 commonly known as cryolite is added to the aluminium oxide thus all 3 are correct, thus option A is the correct answer.

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