TWENTY-FIRST-CENTURY-SCIENCE-CHEMISTRY-B-J258 · Cambridge OCR GCSE (9–1)
TWENTY-FIRST-CENTURY-SCIENCE-CHEMISTRY-B-J258/41
Depth in Chemistry (Higher Tier)
Twenty First Century Science Chemistry B · June 2023 · Variant 1
Relative difficulty
Analysis source: OCR
Analysis aligned to the official syllabus and assessment design.
3.5 / 5
180
210 min
Quantitative and Practical Chemistry
Cohort performance
Session statistics from official examination reports
Total marks
180
Duration
210 min
Session difficulty
3.5 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
The June 2023 OCR GCSE Chemistry B papers (J258/03 and J258/04) provided a balanced but rigorous test of students' knowledge, combining fundamental recall with a high density of quantitative and practical analysis questions.
The papers are rated as a 3.5 out of 5 in terms of difficulty.
While many multiple-choice and short-answer questions offered accessible entry points, several multi-step calculation questions (such as scaling atomic radii, converting parts per million to percentages, and bond energy stoichiometry) tested mathematical fluency.
Additionally, the drawing requirements for displayed formulas and exact functional group circling demanded high levels of precision.
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.
Maths and Calculation
Weight: 8100%Recall and Knowledge
Weight: 675%Experimental
Weight: 450%Interpretation Chemical
Weight: 338%Equation
Weight: 113%
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 9
Approx. 73% of maximum mark
Level 8
Approx. 63% of maximum mark
Level 7
Approx. 54% of maximum mark
Level 6
Approx. 44% of maximum mark
Level 5
Approx. 33% of maximum mark
Level 4
Approx. 23% of maximum mark
Level 3
Approx. 17% 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.
State features in sequence or list observable properties — do not explain causes unless asked.
Show formula, substitution, and unit; method marks need visible working.
Match the expected response style for “State” questions.
Match the expected response style for “Draw” questions.
Match the expected response style for “Name” questions.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 1.2
Min per mark: 1.1
Syllabus traceability
Topics linked to questions and mark weighting in this session
How are the amounts of chemicals in solution measured? (Chemical analysis)
16 marks this session
What is the evidence for climate change, why is it occurring? (Air and water)
15 marks this session
How have our ideas about atoms developed over time? (Chemical patterns)
15 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
How do bonding and structure affect properties of materials?
How do chemists control the rate of reactions?
Why is crude oil important as a source of new materials?
How do bonding and structure affect properties of materials? (Material choices)
How do chemists control the rate of reactions? (Making useful chemicals)
How has the Earth’s atmosphere changed over time, and why? (Air and water)
How are the amounts of chemicals in solution measured? (Chemical analysis)
What is the evidence for climate change, why is it occurring? (Air and water)
Paper comparison
Marks and duration breakdown across papers in this session
J258/03 Breadth in Chemistry (Higher Tier): J258/04 Depth in Chemistry (Higher Tier):
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
How are the amounts of chemicals in solution measured? (Chemical analysis)
16 marks this session
Practise in RevuiWhat is the evidence for climate change, why is it occurring? (Air and water)
15 marks this session
Practise in RevuiHow have our ideas about atoms developed over time? (Chemical patterns)
15 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 GCSE Chemistry B papers (J258/03 and J258/04) provided a balanced but rigorous test of students' knowledge, combining fundamental recall with a high density of quantitative and practical analysis questions.
- 2Message
The papers are rated as a 3.5 out of 5 in terms of difficulty.
- 3Message
While many multiple-choice and short-answer questions offered accessible entry points, several multi-step calculation questions (such as scaling atomic radii, converting parts per million to percentages, and bond energy stoichiometry) tested mathematical fluency.
- 4Message
Additionally, the drawing requirements for displayed formulas and exact functional group circling demanded high levels of precision.
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2023 2023
Twenty First Century Science Chemistry B
The June 2023 OCR GCSE Chemistry B papers (J258/03 and J258/04) provided a balanced but rigorous test of students' knowledge, combining fundamental recall with a high density of quantitative and practical analysis questions. The papers are rated as a 3.5 out of 5 in terms of diff
The June 2023 OCR GCSE Chemistry B papers (J258/03 and J258/04) provided a balanced but rigorous test of students' knowledge, combining fundamental recall with a high density of quantitative and practical analysis questions.
The papers are rated as a 3.5 out of 5 in terms of difficulty.
While many multiple-choice and short-answer questions offered accessible entry points, several multi-step calculation questions (such as scaling atomic radii, converting parts per million to percentages, and bond energy stoichiometry) tested mathematical fluency.
- Total marks
- 180
- Duration
- 210 min
- Session difficulty
- 3.5 / 5
Session analysis
The June 2023 OCR GCSE Chemistry B papers (J258/03 and J258/04) provided a balanced but rigorous test of students' knowledge, combining fundamental recall with a high density of quantitative and practical analysis questions. The papers are rated as a 3.5 out of 5 in terms of difficulty. While many multiple-choice and short-answer questions offered accessible entry points, several multi-step calculation questions (such as scaling atomic radii, converting parts per million to percentages, and bond energy stoichiometry) tested mathematical fluency. Additionally, the drawing requirements for displayed formulas and exact functional group circling demanded high levels of precision.
Updated Jun 14, 2026
Paper breakdown
J258/03 Breadth in Chemistry (Higher Tier): J258/04 Depth in Chemistry (Higher Tier):
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.
78% 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 & Structured
80·30·44%
Quantitative & Calculation
45·12·25%
Multiple Choice & Tick Box
35·15·19%
Extended Response
(LOR)
20·3·11%
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.
J258/03 Recall & Ap
0.88 m/minJ258/04 Structured
0.85 m/minTotal marks
90
Total time
104 min
Avg pace
0.87
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.
What are electrolytes and what happens during electrolysis?
90%90%
How do chemists control the rate of reactions?
85%85%
Why is crude oil important as a source of new materials?
80%80%
Overall Difficulty Verdict
The June 2023 OCR GCSE Chemistry B papers (J258/03 and J258/04) provided a balanced but rigorous test of students' knowledge, combining fundamental recall with a high density of quantitative and practical analysis questions. The papers are rated as a 3.5 out of 5 in terms of difficulty. While many multiple-choice and short-answer questions offered accessible entry points, several multi-step calculation questions (such as scaling atomic radii, converting parts per million to percentages, and bond energy stoichiometry) tested mathematical fluency. Additionally, the drawing requirements for displayed formulas and exact functional group circling demanded high levels of precision.
Exam tips
Paper format
- Duration
- 1h 45min
- Total marks
- 90
- Weighting
- 50%
- Question types
- Multiple Choice / Tick Box, Short Answer / Structured, Calculations, Level of Response (Extended Writing)
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.