A-LevelChemistryElectrochemistryOct/Nov 2024Paper 1 Q121 Mark

The equation for the reaction of aqueous thiosulfate ions, S2O3²⁻, and aqueous dioxo-vanadium ions, VO2⁺, is shown. 2S2O3²⁻ + XVO2⁺ + yH⁺ → S4O6²⁻ + zVO²⁺ + 2H2O Which row shows two correct statements about the equation for this reaction?

Q: What topic does this question test?

This question tests Electrochemistry in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Ax and z are the same value and quarter the value of y from +4 to +5

Bx and z are the same value and quarter the value of y from +5 to +4

Cx and z are the same value and half the value of y from +5 to +4

Dx and z are the same value and half the value of y from +4 to +5

✓ Correct Answer

The correct answer is C: x and z are the same value and half the value of y from +5 to +4

📋 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...

🎯 Mark Scheme Breakdown

Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.

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About This A-Level Chemistry Question

Topic

This multiple-choice question tests Electrochemistry in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Chemistry Oct/Nov 2024 examination, Paper 1 Variant 2.

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