CHEMISTRY-B-SALTERS-H433 · Cambridge OCR A Level
CHEMISTRY-B-SALTERS-H433/21
Paper 2
Chemistry B Salters · June 2023 · Variant 1
Relative difficulty
Analysis source: OCR
Analysis aligned to the official syllabus and assessment design.
3.8 / 5
270
360 min
Kinetics and reaction mechanisms, representing a combined 38 marks across the series.
Cohort performance
Session statistics from official examination reports
Total marks
270
Duration
360 min
Session difficulty
3.8 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
The June 2023 OCR A-Level Chemistry B (Salters) H433 examination presented a challenging and balanced set of papers, maintaining a difficulty rating of 3.8 out of 5.0 (4 Stars).
While Paper 1 (Fundamentals of Chemistry) tested the core syllabus with several standard mathematical steps, Paper 2 (Scientific Literacy) demanded exceptional comprehension of unfamiliar contexts, particularly in the questions relating to the Calcium Carbide Advance Notice Article.
Paper 3 (Practical Skills) pushed candidates to articulate deep mechanistic and structural logic, specifically within transition metal complexation and the iodination of propanone kinetics.
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: 5100%Mechanistic and S
Weight: 480%Experimental
Weight: 360%Logical
Weight: 240%Reasoning
Weight: 120%
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. 78% of maximum mark
Level A
Approx. 66% of maximum mark
Level B
Approx. 54% of maximum mark
Level C
Approx. 43% of maximum mark
Level D
Approx. 31% of maximum mark
Level E
Approx. 20% 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
Show formula, substitution, and unit; method marks need visible working.
Give reasons and link mechanism to outcome; each point needs a because/so chain.
State features in sequence or list observable properties — do not explain causes unless asked.
Match the expected response style for “State” questions.
Match the expected response style for “Draw” questions.
Present multiple perspectives with evidence; balance breadth and depth.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Match the expected response style for “Name” questions.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 35
Min per mark: 1.5
Min per mark: 1.2
Syllabus traceability
Topics linked to questions and mark weighting in this session
Kinetics (Developing fuels (DF))
19 marks this session
Bonding and structure (Colour by design (CD))
16 marks this session
Equilibria (acid–base) (Elements of life (EL))
13 marks this session
Formulae, equations and amount of substance (Developing metals (DM))
12 marks this session
Redox (Elements from the sea (ES))
12 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
Redox (Elements from the sea (ES))
Modern analytical techniques (Polymers and life (PL))
Formulae, equations and amount of substance (Elements from the sea (ES))
Kinetics (Developing fuels (DF))
Bonding and structure (Colour by design (CD))
Equilibrium (The chemical industry (CI))
Equilibria (acid–base) (Elements of life (EL))
Formulae, equations and amount of substance (Developing metals (DM))
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
H433/01 Fundamentals of Chemistry: H433/02 Scientific literacy in chemistry: H433/03 Practical skills in 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
Kinetics (Developing fuels (DF))
19 marks this session
Practise in RevuiBonding and structure (Colour by design (CD))
16 marks this session
Practise in RevuiEquilibria (acid–base) (Elements of life (EL))
13 marks this session
Practise in RevuiFormulae, equations and amount of substance (Developing metals (DM))
12 marks this session
Practise in RevuiRedox (Elements from the sea (ES))
12 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
The June 2023 OCR A-Level Chemistry B (Salters) H433 examination presented a challenging and balanced set of papers, maintaining a difficulty rating of 3.8 out of 5.0 (4 Stars).
- 2Message
While Paper 1 (Fundamentals of Chemistry) tested the core syllabus with several standard mathematical steps, Paper 2 (Scientific Literacy) demanded exceptional comprehension of unfamiliar contexts, particularly in the questions relating to the Calcium Carbide Advance Notice Article.
- 3Message
Paper 3 (Practical Skills) pushed candidates to articulate deep mechanistic and structural logic, specifically within transition metal complexation and the iodination of propanone kinetics.
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2023 2023
Chemistry B Salters
The June 2023 OCR A-Level Chemistry B (Salters) H433 examination presented a challenging and balanced set of papers, maintaining a difficulty rating of 3.8 out of 5.0 (4 Stars). While Paper 1 (Fundamentals of Chemistry) tested the core syllabus with several standard mathematical
The June 2023 OCR A-Level Chemistry B (Salters) H433 examination presented a challenging and balanced set of papers, maintaining a difficulty rating of 3.8 out of 5.0 (4 Stars).
While Paper 1 (Fundamentals of Chemistry) tested the core syllabus with several standard mathematical steps, Paper 2 (Scientific Literacy) demanded exceptional comprehension of unfamiliar contexts, particularly in the questions relating to the Calcium Carbide Advance Notice Article.
Paper 3 (Practical Skills) pushed candidates to articulate deep mechanistic and structural logic, specifically within transition metal complexation and the iodination of propanone kinetics.
- Total marks
- 270
- Duration
- 360 min
- Session difficulty
- 3.8 / 5
Session analysis
The June 2023 OCR A-Level Chemistry B (Salters) H433 examination presented a challenging and balanced set of papers, maintaining a difficulty rating of 3.8 out of 5.0 (4 Stars). While Paper 1 (Fundamentals of Chemistry) tested the core syllabus with several standard mathematical steps, Paper 2 (Scientific Literacy) demanded exceptional comprehension of unfamiliar contexts, particularly in the questions relating to the Calcium Carbide Advance Notice Article. Paper 3 (Practical Skills) pushed candidates to articulate deep mechanistic and structural logic, specifically within transition metal complexation and the iodination of propanone kinetics.
Updated Jun 14, 2026
Paper breakdown
H433/01 Fundamentals of Chemistry: H433/02 Scientific literacy in chemistry: H433/03 Practical skills in 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.
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.
Short Answer Questions
150·68·56%
Structured Calculations & Long Answer Questions
60·18·22%
Multiple Choice Questions
30·30·11%
Level of Response (LOR) Essays
30·5·11%
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 1 Section A (…
0.84 m/minPaper 1 Section B (…1
0.03 m/minPaper 2 (Scientific…
0.67 m/minTotal marks
141
Total time
220 min
Avg pace
0.64
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Modern analytical techniques (Polymers and life (PL))
95%95%
Inorganic chemistry and the periodic table (Developing fuels (DF))
82%82%
Kinetics (Polymers and life (PL))
78%78%
Executive Difficulty Verdict
The June 2023 OCR A-Level Chemistry B (Salters) H433 examination presented a challenging and balanced set of papers, maintaining a difficulty rating of 3.8 out of 5.0 (4 Stars). While Paper 1 (Fundamentals of Chemistry) tested the core syllabus with several standard mathematical steps, Paper 2 (Scientific Literacy) demanded exceptional comprehension of unfamiliar contexts, particularly in the questions relating to the Calcium Carbide Advance Notice Article. Paper 3 (Practical Skills) pushed candidates to articulate deep mechanistic and structural logic, specifically within transition metal complexation and the iodination of propanone kinetics.
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.