Question

4(a)(ii). Sodium and aluminium are extracted by the electrolysis of molten sodium chloride and alumina respectively. Write balanced equations for the reactions at the anode and cathode during the extraction of: I. sodium; II. aluminium.

Accepted Answer

For sodium (electrolysis of molten NaCl):
At the anode: 2Cl⁻(l)→Cl₂(g)+2e⁻
At the cathode: Na⁺(l)+e⁻→Na(s)

For aluminium (electrolysis of molten Al₂O₃):
At the anode: 2O²⁻(l)→O₂(g)+4e⁻
At the cathode: Al³⁺(l)+3e⁻→Al(s)

WAEC Chemistry 2014 Theory — Question 29

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