A-LevelChemistryElectrochemistryMay/June 2016Paper 1 Q91 Mark
In the treatment of domestic water supplies, chlorine is added to the water to form HClO. Cl₂(aq) + H₂O(l) → H⁺(aq) + Cl⁻(aq) + HClO(aq) The HClO reacts further to give ClO⁻ ions. HClO(aq) + H₂O(l) ⇌ H₃O⁺(aq) + ClO⁻(aq) Both HClO and ClO⁻ kill bacteria by oxidation. What is the change in oxidation number of chlorine when forming the ClO⁻ ion from aqueous chlorine?
A-1
B0
C+1
D+2
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The correct answer is C. This question tests the candidate's understanding of electrochemistry within the Chemistrysyllabus. The examiner's mark scheme requires...
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