CHEMISTRY · IB Diploma Programme
CHEMISTRY/21
Paper 2
Chemistry · June 2025 · Variant 1
Relative difficulty
Analysis source: International Baccalaureate Organization
Analysis aligned to the official syllabus and assessment design.
3.4 / 5
105
180 min
Green Chemistry and Experimental Methods
Cohort performance
Session statistics from official examination reports
Total marks
105
Duration
180 min
Session difficulty
3.4 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
A highly balanced exam with an exceptionally strong emphasis on experimental inquiry (Green Chemistry/Methods) and the core mole concept, penalizing students who lacked precise laboratory protocol knowledge.
Compare difficulty across recent years. Compare topic weight by year to spot recurring and returning areas.
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
Skill weighting
Shows the skill mix this paper tested most heavily.
Mathematical & Calculation
Weight: 7100%Analysis & G
Weight: 686%Chemical Nomenclature
Weight: 571%Experimental
Weight: 343%Theoretical Explanation
Weight: 229%
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
Report type
IB subject report — grade distributions, IA weighting, and HL/SL distinctions
Level 7
Excellent — top band for competitive university offers
Level 6
Very good — strong HL performance
Level 5
Good — solid pass at higher level
Level 4
Satisfactory — minimum for many university credits
Level 3
Mediocre
Level 2
Poor
Level 1
Very poor
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
Match the expected response style for “Deduce” questions.
Give reasons and link mechanism to outcome; each point needs a because/so chain.
Match the expected response style for “Determine” questions.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Show formula, substitution, and unit; method marks need visible working.
Match the expected response style for “State” questions.
Match the expected response style for “Outline” questions.
State features in sequence or list observable properties — do not explain causes unless asked.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 1.8
Min per mark: 1.5
Syllabus traceability
Topics linked to questions and mark weighting in this session
Green Chemistry and Experimental Methods
23 marks this session
Counting particles by mass: The mole
13 marks this session
Functional groups: Classification of organic compounds
12 marks this session
The covalent model (Models of bonding and structure)
11 marks this session
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
Counting particles by mass: The mole
Green Chemistry and Experimental Methods
Option D: Medicinal Chemistry
The covalent model
Measurements, Uncertainties and Spectroscopy
Electron transfer reactions
How fast? The rate of chemical change
Functional groups: Classification of organic compounds
Paper comparison
Marks and duration breakdown across papers in this session
Paper 1A (Multiple Choice):
Paper 1B (Data Analysis & Practical):
Paper 2 (Structured):
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
Green Chemistry and Experimental Methods
23 marks this session
Practise in RevuiCounting particles by mass: The mole
13 marks this session
Practise in RevuiFunctional groups: Classification of organic compounds
12 marks this session
Practise in RevuiThe covalent model (Models of bonding and structure)
11 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
A highly balanced exam with an exceptionally strong emphasis on experimental inquiry (Green Chemistry/Methods) and the core mole concept, penalizing students who lacked precise laboratory protocol knowledge.
- 2Message
Compare difficulty across recent years. Compare topic weight by year to spot recurring and returning areas.
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2025 2025
Chemistry
A highly balanced exam with an exceptionally strong emphasis on experimental inquiry (Green Chemistry/Methods) and the core mole concept, penalizing students who lacked precise laboratory protocol knowledge.
A highly balanced exam with an exceptionally strong emphasis on experimental inquiry (Green Chemistry/Methods) and the core mole concept, penalizing students who lacked precise laboratory protocol knowledge.
Compare difficulty across recent years. Compare topic weight by year to spot recurring and returning areas.
- Total marks
- 105
- Duration
- 180 min
- Session difficulty
- 3.4 / 5
Session analysis
A highly balanced exam with an exceptionally strong emphasis on experimental inquiry (Green Chemistry/Methods) and the core mole concept, penalizing students who lacked precise laboratory protocol knowledge.
Updated Jun 14, 2026
Paper breakdown
Paper 1A (Multiple Choice):
Paper 1B (Data Analysis & Practical):
Paper 2 (Structured):
Top chapters
Exam structure insights
Marks by chapter
See where the marks were concentrated so revision time goes to the highest-value topics.
Mark accessibility
Estimate which marks were basic, mid-level, or high-difficulty.
76% within easy or medium reach
Command word frequency
Spot common command words so answers match the expected response style.
Question type mix
Compare the mark share of each paper section and question type.
Paper 2)
50·25·48%
Paper 1A)
30·30·29%
Paper 1B)
25·11·24%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Difficulty trend
Compare difficulty across recent years.
Time vs marks
Compare marks with suggested time allocation to plan exam pacing.
Paper 1A
0.67 m/minPaper 1B
0.56 m/minTotal marks
55
Total time
90 min
Avg pace
0.61
Cumulative marks ladder
The line is your running mark total question by question; dashed lines are the estimated grade cut-offs. See which question the line crosses your target grade at, so you know how far you must answer cleanly and which questions decide a band.
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Proton transfer reactions
85%85%
The periodic table: Classification of elements
80%80%
Energy cycles in reactions
75%75%
Exam tips
Paper format
- Duration
- 2h 30min
- Total marks
- 90
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.