CHEMISTRY · 2021
Chemistry
Official National Center for University Entrance Examinations examination materials and examiner commentary for Chemistry (2021). Refer to the board portal for the latest published reports.
Cohort performance
Session statistics from official examination reports
No data available in official reports
Key examiner messages
Top priorities from the principal examiner before you revise
No data available in official reports
Question difficulty map
How candidates performed on each question in this series
No data available in official reports
Assessment objectives
Skill and AO weighting from official examiner commentary
No data available in official reports
Method marks watchlist
Where working, steps, or method marks were commonly lost
No data available in official reports
Recurring mistakes across years
Themes examiners flag in multiple recent sessions for this subject
Stoichiometry: Using mass ratios from coefficients instead of mole ratios. — Convert all given quantities to moles before applying the ba…
Equilibrium: Reversing the sign of concentration change in an ICE table. — Define the reaction direction and write coefficient-scaled cha…
Acid-base: Assuming equal volumes mean neutralization. — Compare moles of H+ and OH- using concentration x volume x valence.
Organic chemistry: Identifying compounds from formula alone without functional-group behavior. — Use reaction tests and structural featur…
Redox: Forgetting that oxidation number can change without visible oxygen transfer. — Calculate oxidation numbers systematically for the …
Question choice intelligence
Mean scores and popularity for optional questions (HKDSE electives)
No data available in official reports
Level exemplars
What candidate scripts at each grade level looked like
No data available in official reports
Grade & admission context
How marks relate to grade thresholds and entry standards
No data available in official reports
Deep insights
What top candidates did
Techniques and approaches examiners rewarded in this series
No data available in official reports
Command word playbook
How to match each command word to the expected response style
No data available in official reports
Time traps
Sections where candidates spent disproportionate time relative to marks
No data available in official reports
Syllabus traceability
Topics linked to questions and mark weighting in this session
No data available in official reports
MCQ trap analytics
Commonly chosen wrong options from examiner commentary
No data available in official reports
Topic heatmap across years
Mark concentration by topic and exam year for this subject
Mark intensity
Stoichiometry, acids/bases, redox and equilibrium
Organic compounds, polymers and biomolecules
Particles, bonding, states and thermochemistry
Inorganic substances and industrial chemistry
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
No data available in official reports
Marks you can still earn
Where valid approaches outside the mark scheme may still gain credit
No data available in official reports
Practise what examiners flagged
Target weak topics from this report inside the Revui app
No data available in official reports
Self-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Pitfall
Stoichiometry: Using mass ratios from coefficients instead of mole ratios. — Convert all given quantities to moles before applying the ba…
- 2Pitfall
Equilibrium: Reversing the sign of concentration change in an ICE table. — Define the reaction direction and write coefficient-scaled cha…
- 3Pitfall
Acid-base: Assuming equal volumes mean neutralization. — Compare moles of H+ and OH- using concentration x volume x valence.
- 4Pitfall
Organic chemistry: Identifying compounds from formula alone without functional-group behavior. — Use reaction tests and structural featur…
- 5Pitfall
Redox: Forgetting that oxidation number can change without visible oxygen transfer. — Calculate oxidation numbers systematically for the …
Teacher briefing pack
One-page session summary for tutors and classroom review
2021 2021
Chemistry
Official National Center for University Entrance Examinations examination materials and examiner commentary for Chemistry (2021). Refer to the board portal for the latest published reports.
Stoichiometry: Using mass ratios from coefficients instead of mole ratios. — Convert all given quantities to moles before applying the ba…
Equilibrium: Reversing the sign of concentration change in an ICE table. — Define the reaction direction and write coefficient-scaled cha…
Revui has indexed this report from the official exam board. Open the original examiner report for full comments on candidates' performance. Curated charts and pitfalls for this series are coming soon.
View official report