9701 · Cambridge International A Level
9701/21
(AS Level Structured Questions)
Chemistry · June 2025 · Variant 1
Relative difficulty
Analysis source: Cambridge Assessment International Education
Analysis aligned to the official syllabus and assessment design.
3.8 / 5
270
465 min
Atoms, molecules and stoichiometry (Quantitative Analysis & Calculations)
Cohort performance
Session statistics from official examination reports
Total marks
270
Duration
465 min
Session difficulty
3.8 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
The May/June 2025 Cambridge International AS & A Level Chemistry (9701) papers present a rigorous, intellectually demanding set of assessments.
Across the five papers, students are challenged not only on their core factual recall but also heavily on their mathematical stoichiometry, structural logical synthesis, and precise experimental analysis.
The exam represents a high standard of chemical education, emphasizing the integration of physical concepts with practical execution.
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 and
Weight: 6100%Practical and
Weight: 583%Logical and Mechanics
Weight: 467%Recall and Periods
Weight: 233%
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
Cambridge Principal Examiner Report — component performance and international standards
Level A*
Approx. 78% of maximum mark
Level A
Approx. 68% of maximum mark
Level B
Approx. 58% of maximum mark
Level C
Approx. 47% of maximum mark
Level D
Approx. 37% of maximum mark
Level E
Approx. 26% of maximum mark
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
Give reasons and link mechanism to outcome; each point needs a because/so chain.
Show formula, substitution, and unit; method marks need visible working.
Match the expected response style for “State” questions.
State features in sequence or list observable properties — do not explain causes unless asked.
Match the expected response style for “Deduce” questions.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Match the expected response style for “Draw” questions.
Name or point to the specific feature asked for — avoid extra explanation.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 20
Min per mark: 2.5
Min per mark: 1.3
Min per mark: 0
Syllabus traceability
Topics linked to questions and mark weighting in this session
Atoms, molecules and stoichiometry (Physical chemistry (AS Level))
45 marks this session
Chemistry of transition elements (Inorganic chemistry (A Level))
35 marks this session
Reaction kinetics (Physical chemistry (A Level))
35 marks this session
Organic synthesis (Organic chemistry (AS Level))
34 marks this session
Arenes (Hydrocarbons)
26 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
Chemistry of transition elements
Atoms, molecules and stoichiometry (Physical chemistry (AS Level))
Organic synthesis
Chemistry of transition elements (Inorganic chemistry (A Level))
Reaction kinetics (Physical chemistry (A Level))
Organic synthesis (Organic chemistry (AS Level))
Electrochemistry
Arenes (Hydrocarbons)
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
Paper 11 (Multiple Choice):
Paper 21 (AS Level Structured Questions):
Paper 31 (Advanced Practical Skills 1):
Paper 41 (A Level Structured Questions):
Paper 51 (Planning, Analysis and Evaluation):
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
Atoms, molecules and stoichiometry (Physical chemistry (AS Level))
45 marks this session
Practise in RevuiChemistry of transition elements (Inorganic chemistry (A Level))
35 marks this session
Practise in RevuiReaction kinetics (Physical chemistry (A Level))
35 marks this session
Practise in RevuiOrganic synthesis (Organic chemistry (AS Level))
34 marks this session
Practise in RevuiArenes (Hydrocarbons)
26 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
The May/June 2025 Cambridge International AS & A Level Chemistry (9701) papers present a rigorous, intellectually demanding set of assessments.
- 2Message
Across the five papers, students are challenged not only on their core factual recall but also heavily on their mathematical stoichiometry, structural logical synthesis, and precise experimental analysis.
- 3Message
The exam represents a high standard of chemical education, emphasizing the integration of physical concepts with practical execution.
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2025 2025
Chemistry
The May/June 2025 Cambridge International AS & A Level Chemistry (9701) papers present a rigorous, intellectually demanding set of assessments. Across the five papers, students are challenged not only on their core factual recall but also heavily on their mathematical stoichiomet
The May/June 2025 Cambridge International AS & A Level Chemistry (9701) papers present a rigorous, intellectually demanding set of assessments.
Across the five papers, students are challenged not only on their core factual recall but also heavily on their mathematical stoichiometry, structural logical synthesis, and precise experimental analysis.
The exam represents a high standard of chemical education, emphasizing the integration of physical concepts with practical execution.
- Total marks
- 270
- Duration
- 465 min
- Session difficulty
- 3.8 / 5
Session analysis
The May/June 2025 Cambridge International AS & A Level Chemistry (9701) papers present a rigorous, intellectually demanding set of assessments. Across the five papers, students are challenged not only on their core factual recall but also heavily on their mathematical stoichiometry, structural logical synthesis, and precise experimental analysis. The exam represents a high standard of chemical education, emphasizing the integration of physical concepts with practical execution.
Updated Jun 12, 2026
Paper breakdown
Paper 11 (Multiple Choice):
Paper 21 (AS Level Structured Questions):
Paper 31 (Advanced Practical Skills 1):
Paper 41 (A Level Structured Questions):
Paper 51 (Planning, Analysis and Evaluation):
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.
Structured Questions
(A Level)
100·10·37%
Structured Questions
(AS Level)
60·6·22%
Multiple Choice
(Paper 1)
40·40·15%
Practical Skills
(AS Level)
40·3·15%
Planning and Evaluation
(A Level)
30·2·11%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Time vs marks
Compare marks with suggested time allocation to plan exam pacing.
Paper 11 (Multiple …
0.80 m/minPaper 21 (AS Level …
20.05 m/minPaper 31 (Advanced …1
0.05 m/minPaper 41 (A Level S…
0.40 m/minTotal marks
492
Total time
190 min
Avg pace
2.59
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Isomerism: structural isomerism and stereoisomerism
90%90%
Electrolysis
85%85%
Some reactions of the halide ions
80%80%
Expert Examiner Verdict: May/June 2025 Series Analysis
The May/June 2025 Cambridge International AS & A Level Chemistry (9701) papers present a rigorous, intellectually demanding set of assessments. Across the five papers, students are challenged not only on their core factual recall but also heavily on their mathematical stoichiometry, structural logical synthesis, and precise experimental analysis. The exam represents a high standard of chemical education, emphasizing the integration of physical concepts with practical execution.
Examiner notes & key calculations
- Incorrect units and rounding: Many students lose marks in kinetics and cell calculations by not converting temperature to Kelvin or rounding intermediate answers too early.
- State symbols omission: When writing fundamental equations like first ionisation energy, candidates frequently omit the compulsory gas state symbols Fe(g)→Fe+(g)+e− \text{Fe(g)} \rightarrow \text{Fe}^+\text{(g)} + e^- Fe(g)→Fe+(g)+e−.
- Burette reading precision: In Paper 31, failing to record all burette volumes to the nearest 0.05 cm³ (e.g., writing 24.1 instead of 24.10) is a chronic mistake.
- Vague IR interpretation: When analyzing infrared spectra, students must state both the specific bond (e.g., C=O \text{C=O} C=O) and the exact functional group (e.g., ester) responsible for the absorption range.
Exam tips
Paper format
- Duration
- 1h 15min
- Total marks
- 60
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.