7405 · AQA A Level
7405/21
Paper 2
Chemistry · June 2023 · Variant 1
Relative difficulty
Analysis source: AQA
Analysis aligned to the official syllabus and assessment design.
4.0 / 5
300
360 min
Organic Analysis & Practical Techniques
Cohort performance
Session statistics from official examination reports
Total marks
300
Duration
360 min
Session difficulty
4.0 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
This exam series represents a high-difficulty benchmark for A-level candidates.
While foundational definitions and simple mechanisms provided accessible starting points, the paper rapidly escalated into high-cognitive-demand calculations and synoptic synthesis.
Key barriers to top marks included the multi-step EDTA back-titration, saturated calcium hydroxide pH calculations involving solubility and KwK_wKw, and detailed mechanistic explanations requiring precise chemical terminology.
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%Practical & Experimental
Weight: 686%Mechanistic Reasoning
Weight: 457%Theoretical Recall
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. 83% of maximum mark
Level A
Approx. 70% of maximum mark
Level B
Approx. 58% of maximum mark
Level C
Approx. 45% of maximum mark
Level D
Approx. 33% of maximum mark
Level E
Approx. 21% 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.
Match the expected response style for “Deduce” questions.
Match the expected response style for “State” questions.
Match the expected response style for “Draw” questions.
Apply knowledge to an unfamiliar context; concise, practical points score best.
Time traps
Sections where candidates spent disproportionate time relative to marks
No data available in official reports
Syllabus traceability
Topics linked to questions and mark weighting in this session
Organic analysis
31 marks this session
Organic synthesis
27 marks this session
Acids and bases
24 marks this session
Reactions of ions in aqueous solution
23 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 synthesis
Acids and bases
Rate equations
Transition metals
Organic analysis
Reactions of ions in aqueous solution
Group 2, the alkaline earth metals
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
7405/1 Inorganic and Physical Chemistry: 7405/2 Organic and Physical Chemistry: 7405/3 Synoptic, Practical and MCQs:
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
Organic analysis
31 marks this session
Practise in RevuiOrganic synthesis
27 marks this session
Practise in RevuiAcids and bases
24 marks this session
Practise in RevuiReactions of ions in aqueous solution
23 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 represents a high-difficulty benchmark for A-level candidates.
- 2Message
While foundational definitions and simple mechanisms provided accessible starting points, the paper rapidly escalated into high-cognitive-demand calculations and synoptic synthesis.
- 3Message
Key barriers to top marks included the multi-step EDTA back-titration, saturated calcium hydroxide pH calculations involving solubility and KwK_wKw, and detailed mechanistic explanations requiring precise chemical terminology.
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2023 2023
Chemistry
This exam series represents a high-difficulty benchmark for A-level candidates. While foundational definitions and simple mechanisms provided accessible starting points, the paper rapidly escalated into high-cognitive-demand calculations and synoptic synthesis. Key barriers to to
This exam series represents a high-difficulty benchmark for A-level candidates.
While foundational definitions and simple mechanisms provided accessible starting points, the paper rapidly escalated into high-cognitive-demand calculations and synoptic synthesis.
Key barriers to top marks included the multi-step EDTA back-titration, saturated calcium hydroxide pH calculations involving solubility and KwK_wKw, and detailed mechanistic explanations requiring precise chemical terminology.
- Total marks
- 300
- Duration
- 360 min
- Session difficulty
- 4.0 / 5
Session analysis
This exam series represents a high-difficulty benchmark for A-level candidates. While foundational definitions and simple mechanisms provided accessible starting points, the paper rapidly escalated into high-cognitive-demand calculations and synoptic synthesis. Key barriers to top marks included the multi-step EDTA back-titration, saturated calcium hydroxide pH calculations involving solubility and KwK_wKw, and detailed mechanistic explanations requiring precise chemical terminology.
Updated Jun 14, 2026
Paper breakdown
7405/1 Inorganic and Physical Chemistry: 7405/2 Organic and Physical Chemistry: 7405/3 Synoptic, Practical and MCQs:
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.
71% 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 & Practical Description
147·52·49%
Calculations
78·18·26%
Mechanisms & Structures
45·15·15%
Multiple Choice Questions
(MCQ)
30·30·10%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Electrode Potentials & Cells
5%5%
Carbonyl Chemistry (Aldehydes and Ketones)
4%4%
Group 7 (Halogens)
4%4%
Difficulty Verdict
This exam series represents a high-difficulty benchmark for A-level candidates. While foundational definitions and simple mechanisms provided accessible starting points, the paper rapidly escalated into high-cognitive-demand calculations and synoptic synthesis. Key barriers to top marks included the multi-step EDTA back-titration, saturated calcium hydroxide pH calculations involving solubility and KwK_wKw, and detailed mechanistic explanations requiring precise chemical terminology.
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.