What is the correct answer to this A-Level Chemistry question?

Sign up to Oracle Prep to view the full model answer with examiner insights.

A-LevelChemistryGroup 2May/June 2017Paper 4 Q113 Marks

The table lists the standard enthalpy changes of formation, ΔΗ, for some compounds and aqueous ions. ``` species ΔH_f/kJ mol⁻¹ Ba²⁺(aq) -538 OH⁻(aq) -230 CO₂(g) -394 BaCO₃(s) -1216 H₂O(l) -286 ```

Q: What topic does this question test?

This question tests Group 2 in A-Level Chemistry (syllabus code 9701). It is worth 13 marks.

📋 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

Join thousands of Cambridge students already using Oracle Prep

About This A-Level Chemistry Question

Topic

This structured question tests Group 2 in A-Level Chemistry (syllabus code 9701). It is worth 13 marks.

Source

This question appeared in the Cambridge A-Level Chemistry May/June 2017 examination, Paper 4 Variant 1.

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.