CHEMISTRY-8CH0 · Pearson Edexcel AS Level
CHEMISTRY-8CH0/21
Paper 2
Chemistry · 2022 · Variant 1
Relative difficulty
Analysis source: Pearson Edexcel
Analysis aligned to the official syllabus and assessment design.
3.0 / 5
160
180 min
Stoichiometry and Quantitative Laboratory Chemistry
Cohort performance
Session statistics from official examination reports
Total marks
160
Duration
180 min
Session difficulty
3.0 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficulty level (rated 3 stars out of 5).
Paper 1 challenged students primarily on multi-step stoichiometry and structural representations, whilst Paper 2 featured demanding practical synthesis and thermometric analysis questions.
Overall, standard physical chemistry definitions and core calculation structures were widely rewarded.
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
Weight: 7100%Practical Techniques
Weight: 686%Organic
Weight: 457%Reaction Periodicity
Weight: 343%Table
Weight: 114%
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
Examiner report — national grade boundaries and question-level commentary
Level A
Approx. 63% of maximum mark
Level B
Approx. 53% of maximum mark
Level C
Approx. 44% of maximum mark
Level D
Approx. 35% of maximum mark
Level E
Approx. 26% of maximum mark
Deep insights
What top candidates did
Techniques and approaches examiners rewarded in this series
Difficulty Verdict
This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficulty level (rated 3 stars out of 5). Paper 1 challenged students primarily on multi-step stoichiometry and structural representations, whilst Paper 2 featured demanding practical synthesis and thermometric analysis questions. Overall, standard physical chemistry definitions and core calculation struc
Command word playbook
How to match each command word to the expected response style
Show formula, substitution, and unit; method marks need visible working.
Give reasons and link mechanism to outcome; each point needs a because/so chain.
Match the expected response style for “Deduce” questions.
Weigh arguments for and against with evidence; end with a supported judgement.
Match the expected response style for “State” questions.
Match the expected response style for “Draw” questions.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 1.3
Min per mark: 1.1
Min per mark: 1.1
Min per mark: 1
Syllabus traceability
Topics linked to questions and mark weighting in this session
Formulae, Equations and Amounts of Substance (Paper 1)
34 marks this session
Organic Chemistry I
31 marks this session
Bonding and Structure (Paper 1)
18 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
Organic Chemistry I
Formulae, Equations and Amounts of Substance (Paper 1)
Bonding and Structure (Paper 1)
Formulae, Equations and Amounts of Substance (P1)
Energetics I
Atomic Structure and the Periodic Table (P1)
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
Paper 01: Core Inorganic and Physical Chemistry:
Paper 02: Core Organic and Physical Chemistry:
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
Formulae, Equations and Amounts of Substance (Paper 1)
34 marks this session
Practise in RevuiOrganic Chemistry I
31 marks this session
Practise in RevuiBonding and Structure (Paper 1)
18 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficulty level (rated 3 stars out of 5).
- 2Message
Paper 1 challenged students primarily on multi-step stoichiometry and structural representations, whilst Paper 2 featured demanding practical synthesis and thermometric analysis questions.
- 3Message
Overall, standard physical chemistry definitions and core calculation structures were widely rewarded.
- 4Strength
Difficulty Verdict: This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficu
Teacher briefing pack
One-page session summary for tutors and classroom review
2022 2022
Chemistry
This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficulty level (rated 3 stars out of 5). Paper 1 challenged students primarily on multi-step stoichiometry and structural representations, whilst Paper 2 featured demanding practical sy
This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficulty level (rated 3 stars out of 5).
Paper 1 challenged students primarily on multi-step stoichiometry and structural representations, whilst Paper 2 featured demanding practical synthesis and thermometric analysis questions.
Overall, standard physical chemistry definitions and core calculation structures were widely rewarded.
- Total marks
- 160
- Duration
- 180 min
- Session difficulty
- 3.0 / 5
Session analysis
This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficulty level (rated 3 stars out of 5). Paper 1 challenged students primarily on multi-step stoichiometry and structural representations, whilst Paper 2 featured demanding practical synthesis and thermometric analysis questions. Overall, standard physical chemistry definitions and core calculation structures were widely rewarded.
Updated Jun 14, 2026
Paper breakdown
Paper 01: Core Inorganic and Physical Chemistry:
Paper 02: Core Organic and Physical Chemistry:
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.
80% 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.
Short Answer / Structural
64·25·40%
Calculations
52·15·33%
Extended Writing / Practical Discussion
24·4·15%
Multiple Choice
(MCQ)
20·20·13%
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 1 Short Calcu…
0.96 m/minPaper 1 Inorganic E…
0.80 m/minPaper 1 Lab & Pract…
0.90 m/minPaper 2 Physical Ch…
0.88 m/minTotal marks
132
Total time
150 min
Avg pace
0.88
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Aldehyde vs Ketone Practical Identification
5%5%
Group 7 Halogen Halide Displacement Reactions
4%4%
Green Chemistry: Atom Economy vs Yield Calculations
4%4%
Difficulty Verdict
This exam series sitting of Edexcel AS Chemistry (8CH0) was of a standard, highly accessible difficulty level (rated 3 stars out of 5). Paper 1 challenged students primarily on multi-step stoichiometry and structural representations, whilst Paper 2 featured demanding practical synthesis and thermometric analysis questions. Overall, standard physical chemistry definitions and core calculation structures were widely rewarded.
Examiner notes & key calculations
- The Distillation Setup Trap: When evaluating distillation apparatus improvements, students frequently neglected to explain why the thermometer bulb must align with the condenser entrance (to measure the temperature of the vapor, not the liquid).
- Flame Test Descriptions: Candidates frequently confused the physical steps of flame emission. Many incorrectly claimed that 'lower energy levels' was the error rather than recognizing that excitation (moving up) involves absorption, not emission.
- Isotopic Ratios: Many struggled to use probability theory (e.g., 34×14 \frac{3}{4} \times \frac{1}{4} 43×41) to justify the 9:6:1 height ratio of molecular chlorine ion peaks in mass spectra.
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.