Skip to main content
A-LevelChemistryGroup 17May/June 2024Paper 1 Q211 Mark

The table shows statements about some of the properties of halogens and their compounds and explanations for these properties. [Table 21.1] Which row shows a correct statement about the property and a correct explanation for the statement?

Astatement: iodine is a solid at room temperature, explanation: the I–I bond strength is high
Bstatement: the decomposition of hydrogen iodide is more endothermic than the decomposition of hydrogen chloride, explanation: chlorine is more reactive than iodine
Cstatement: when chlorine is bubbled into aqueous potassium iodide, a purple solution is seen, explanation: chlorine is a stronger oxidising agent than iodine
Dstatement: when concentrated sulfuric acid is added to solid potassium iodide, a purple vapour is seen, explanation: iodide ions are being oxidised to iodine by the sulfuric acid

✓ Correct Answer

The correct answer is D: statement: when concentrated sulfuric acid is added to solid potassium iodide, a purple vapour is seen, explanation: iodide ions are being oxidised to iodine by the 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.

🔒

Unlock the Examiner's Analysis

Sign up for free to reveal the full examiner report, trap analysis, and mark scheme breakdown for this question.

Sign Up Free to Unlock →

Join thousands of Cambridge students already using Oracle Prep

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 May/June 2024 examination, Paper 1 Variant 2.

Practice on Oracle Prep

Oracle Prep provides AI-powered practice for all Cambridge O-Level and A-Level subjects. Our platform includes topic predictions with 87.7% accuracy, AI essay grading, and a comprehensive question bank spanning 25 years of past papers across 29 subjects.

Related Chemistry Questions

© 2026 Oracle Prep — The AI-Powered Cambridge Exam Engine