CHEMISTRY · Common Test for University Admissions (大学入学共通テスト)
CHEMISTRY/11
Chemistry
Chemistry · 2020 · Variant 1
Relative difficulty
Analysis source: National Center for University Entrance Examinations (DNC)
Analysis aligned to the official syllabus and assessment design.
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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
No data available in official reports
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
No data available in official reports
Difficulty trend
How session difficulty has shifted across recent years
No data available in official reports
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
No data available in official reports
Teacher briefing pack
One-page session summary for tutors and classroom review
No data available in official reports
Exam tips
Paper format
- Duration
- 60 min for one science subject / 130 min for two science subjects
- Total marks
- 100
- Weighting
- 100%
- Question types
- Stoichiometry, equilibrium, acid-base, redox, inorganic, organic and polymer chemistry
- Every stoichiometry item starts with the balanced equation. Circle the mole ratio, then convert mass, gas volume or concentration into moles.
- Initial-change-equilibrium tables prevent sign errors in Kc, Kp, solubility and weak-acid/base problems. Keep expressions symbolic until the final substitution.
- Know strong versus weak, concentration versus amount, pH versus neutralization point and indicator range. These distinctions drive titration questions.
Common mistakes
Stoichiometry
Using mass ratios from coefficients instead of mole ratios.
How to avoid: Convert all given quantities to moles before applying the balanced-equation ratio.
Equilibrium
Reversing the sign of concentration change in an ICE table.
How to avoid: Define the reaction direction and write coefficient-scaled changes for every species.
Acid-base
Assuming equal volumes mean neutralization.
How to avoid: Compare moles of H+ and OH- using concentration x volume x valence.
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.