A-LevelChemistryGroup 17Oct/Nov 2020Paper 1 Q171 Mark

Which statement about Group 17 elements and their compounds is correct?

Q: What topic does this question test?

This question tests Group 17 in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

AChlorine reacts with cold concentrated sodium hydroxide to form NaCl and NaClO₃.

BHCl is more thermally stable than HBr because chlorine is less electronegative than bromine.

CIodide ions are oxidised to iodine by concentrated sulfuric acid.

DSilver iodide is soluble in dilute aqueous ammonia.

✓ Correct Answer

The correct answer is C: Iodide ions are oxidised to iodine by concentrated sulfuric acid.

📋 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 Group 17 in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Chemistry Oct/Nov 2020 examination, Paper 1 Variant 2.

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