A-LevelChemistryGroup 179701/12 · Feb/Mar 2020 · Q141 Mark

Hot aqueous sodium hydroxide reacts with chlorine. 6NaOH(aq) + 3Cl2(g) → 5NaCl(aq) + NaClO3(aq) + 3H2O(l) Which statement is correct?

AThe oxidation numbers of chlorine and hydrogen both change in the reaction.

BThe oxidation numbers of chlorine in the products are -1 and +1.

CIf the aqueous sodium hydroxide is cold the reaction produces NaClO instead of NaClO3.

DSodium undergoes disproportionation in this reaction.

✓ Correct answer

C: If the aqueous sodium hydroxide is cold the reaction produces NaClO instead of NaClO3.

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Topic: Group 17, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Feb/Mar 2020 Paper 1 Variant 2, question 14.

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