A-LevelChemistryIntroduction to organic chemistryFeb/Mar 2021Paper 1 Q201 Mark

The structures of citric acid and isocitric acid are shown. [Figure showing structures of citric acid and isocitric acid] How many chiral centres does each acid possess? citric acid isocitric acid A 1 1 B 1 2 C 0 1 D 0 2

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

The correct answer is D: citric acid 0, isocitric acid 2.

Q: What topic does this question test?

This question tests Introduction to organic chemistry in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Acitric acid 1, isocitric acid 1

Bcitric acid 1, isocitric acid 2

Ccitric acid 0, isocitric acid 1

Dcitric acid 0, isocitric acid 2

✓ Correct Answer

The correct answer is D: citric acid 0, isocitric acid 2

📋 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 multiple-choice question tests Introduction to organic chemistry in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Chemistry Feb/Mar 2021 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.