7404 · AQA AS Level
7404/21
Organic and Physical Chemistry
Chemistry · June 2023 · Variant 1
Relative difficulty
Analysis source: AQA
Analysis aligned to the official syllabus and assessment design.
3.5 / 5
160
180 min
Amount of substance
Cohort performance
Session statistics from official examination reports
Total marks
160
Duration
180 min
Session difficulty
3.5 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
The cornerstone of high performance remains Amount of Substance, accounting for a massive 27 marks across both papers.
Students who mastered stoichiometry, back titrations, and gas calculations (PV=nRTPV=nRTPV=nRT) secured a significant advantage.
In contrast, many candidates dropped marks on standard descriptive questions, failing to mention key definitions like "giant lattice" for metallic structures or forgetting to subtract the proton mass (1.0 g1.0\ \text{g}1.0 g) in the electrospray TOF mass calculation.
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%Chemical Mechanism
Weight: 686%Scientific Explanation
Weight: 457%Practical Techniques
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
Examiner report — national grade boundaries and question-level commentary
Level A
Approx. 76% of maximum mark
Level B
Approx. 64% of maximum mark
Level C
Approx. 54% of maximum mark
Level D
Approx. 43% of maximum mark
Level E
Approx. 33% 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.
Match the expected response style for “Draw” questions.
Match the expected response style for “Determine” questions.
Match the expected response style for “Outline” 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: 1.7
Min per mark: 1.7
Min per mark: 1
Syllabus traceability
Topics linked to questions and mark weighting in this session
Amount of substance
27 marks this session
Bonding
16 marks this session
Atomic structure
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
Amount of substance
Bonding
Halogenoalkanes
Chemical equilibria, Le Chatelier’s principle and Kc
Atomic structure
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
Paper 1: Inorganic and Physical Chemistry:
Paper 2: 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
Amount of substance
27 marks this session
Practise in RevuiBonding
16 marks this session
Practise in RevuiAtomic structure
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 cornerstone of high performance remains Amount of Substance, accounting for a massive 27 marks across both papers.
- 2Message
Students who mastered stoichiometry, back titrations, and gas calculations (PV=nRTPV=nRTPV=nRT) secured a significant advantage.
- 3Message
In contrast, many candidates dropped marks on standard descriptive questions, failing to mention key definitions like "giant lattice" for metallic structures or forgetting to subtract the proton mass (1.0 g1.0\ \text{g}1.0 g) in the electrospray TOF mass calculation.
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2023 2023
Chemistry
The cornerstone of high performance remains Amount of Substance, accounting for a massive 27 marks across both papers. Students who mastered stoichiometry, back titrations, and gas calculations (PV=nRTPV=nRTPV=nRT) secured a significant advantage. In contrast, many candidates dro
The cornerstone of high performance remains Amount of Substance, accounting for a massive 27 marks across both papers.
Students who mastered stoichiometry, back titrations, and gas calculations (PV=nRTPV=nRTPV=nRT) secured a significant advantage.
In contrast, many candidates dropped marks on standard descriptive questions, failing to mention key definitions like "giant lattice" for metallic structures or forgetting to subtract the proton mass (1.0 g1.0\ \text{g}1.0 g) in the electrospray TOF mass calculation.
- Total marks
- 160
- Duration
- 180 min
- Session difficulty
- 3.5 / 5
Session analysis
The cornerstone of high performance remains Amount of Substance, accounting for a massive 27 marks across both papers. Students who mastered stoichiometry, back titrations, and gas calculations (PV=nRTPV=nRTPV=nRT) secured a significant advantage. In contrast, many candidates dropped marks on standard descriptive questions, failing to mention key definitions like "giant lattice" for metallic structures or forgetting to subtract the proton mass (1.0 g1.0\ \text{g}1.0 g) in the electrospray TOF mass calculation.
Updated Jun 14, 2026
Paper breakdown
Paper 1: Inorganic and Physical Chemistry:
Paper 2: 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.
75% 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
130·16·81%
multiple-choice
30·30·19%
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
0.60 m/minPaper 1 Section B
1.00 m/minPaper 2 Section A
0.60 m/minTotal marks
95
Total time
115 min
Avg pace
0.83
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Chemical equilibria
90%90%
Oxidation, reduction and redox equations
85%85%
Halogenoalkanes
80%80%
Alcohols
75%75%
Examiner notes & key calculations
- Carbocation Stability vs. Product Stability: Examiners noted a persistent confusion in electrophilic addition explanations. Students must state that the reaction proceeds via the more stable carbocation intermediate (due to the positive inductive effect of alkyl groups), not that the product itself is more stable.
- Uncertainty & Precision: In Paper 2, high-resolution mass spec calculations demanded atomic masses to exactly 4 decimal places. Truncating or rounding too early led to immediate mark loss.
- State Symbols: In Paper 1, writing liquid water instead of gas for the reaction of magnesium with steam (Mg(s)+H2O(g)→MgO(s)+H2(g)Mg(s) + H_2O(g) \rightarrow MgO(s) + H_2(g)Mg(s)+H2O(g)→MgO(s)+H2(g)) was a common error.
- Curly Arrow Precision: Curly arrows must originate precisely from a lone pair or a covalent bond and point directly to the accepting atom. Loose or generic arrows scored zero in reaction mechanisms.
Exam tips
Paper format
- Duration
- 1h 30min
- Total marks
- 80
- Weighting
- 50%
- Question types
- Structured Written Questions, Multiple Choice Questions
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.