Mastering the Pearson Edexcel International A Level Chemistry (YCH11) exam requires high precision in organic mechanisms, meticulous unit conversions in quantitative calculations, and absolute clarity in defining physical chemistry concepts. Top scorers succeed by ensuring exact arrow placement in reaction mechanisms, strictly converting to SI units in thermodynamics and gas laws, and demonstrating thorough practical design capabilities.
読了時間 4 分更新日: 2026年6月21日
試験の概要
試験数
6
満点
440
制限時間
9時間 10分
出題形式
4
試験
時間
配点
問題数
配点比率
出題形式
Unit 1: Structure, Bonding and Introduction to Organic Chemistry
1時間 30分
80
35
40%
Multiple Choice, Short Answer / Calculation
Unit 2: Energetics, Group Chemistry, Halogenoalkanes and Alcohols
1時間 30分
80
33
40%
Multiple Choice, Short Answer / Calculation, Extended Writing (Level of Response)
Unit 3: Practical Skills in Chemistry I
1時間 20分
50
4
20%
Practical Analysis / Graphing / Calculation
Unit 4: Rates, Equilibria and Further Organic Chemistry
1時間 45分
90
39
40%
Multiple Choice, Short Answer / Calculation, Extended Writing (Level of Response)
Unit 5: Transition Metals and Organic Nitrogen Chemistry
1時間 45分
90
39
40%
Multiple Choice, Short Answer / Calculation, Extended Writing (Level of Response)
Unit 6: Practical Skills in Chemistry II
1時間 20分
50
4
20%
Practical Analysis / Graphing / Calculation
評価段階
A*ABCDEU
電卓の規定
A scientific or graphical calculator is permitted. Graphical calculators must be in exam mode with all stored programs and data cleared before the exam; the calculator must not be able to retrieve stored text or formulae.
AO1: Demonstrate knowledge and understanding of science. (35%)
AO2: Apply knowledge and understanding of science in familiar and unfamiliar contexts. (45%)
AO3: Analyse, interpret, and evaluate scientific information, ideas, and evidence. (20%)
過去問と採点基準にもとづいて作成（2023–2026）。
電卓プログラム
Graph: zeros, intersections & turning points
Graphical calculator / GDC (exam mode)
目的: Plot a function to read its roots (zeros), points of intersection, and maxima/minima.
使う場面: Checking solutions, sketching, or solving where an analytic method is hard.
手順
Graph the function(s) and use the built-in zero, intersect and maximum/minimum tools.
試験での注意: Allowed, but clear stored programs/data (graphical calculators in exam mode) and show the required working — unsupported calculator answers score no method marks.
Numerical equation solver
Graphical calculator / GDC (exam mode)
目的: Solve an equation or find a variable numerically when an algebraic route is long or implicit.
使う場面: Iterative or implicit equations, or to confirm an algebraic solution.
手順
Use the equation/zero solver, entering the equation and a sensible starting estimate.
試験での注意: Allowed, but clear stored programs/data (graphical calculators in exam mode) and show the required working — unsupported calculator answers score no method marks.
Numerical integration & differentiation
Graphical calculator / GDC (exam mode)
目的: Evaluate a definite integral \(\int_a^b f(x)\,dx\) or a gradient \(f'(x)\) at a point.
使う場面: Checking calculus answers, or where only a numerical value is needed.
手順
Use the GDC's numeric integral / derivative function with the limits or the point.
試験での注意: Allowed, but clear stored programs/data (graphical calculators in exam mode) and show the required working — unsupported calculator answers score no method marks.
Statistics & probability distributions
Graphical calculator / GDC (exam mode)
目的: 1-var/2-var statistics, linear regression, and cumulative binomial / normal / Poisson probabilities without tables.
使う場面: Statistics questions and hypothesis tests.
手順
Enter data in the statistics editor, or use the distribution menu (binomial cdf, normal cdf, …).
試験での注意: Allowed, but clear stored programs/data (graphical calculators in exam mode) and show the required working — unsupported calculator answers score no method marks.
よくあるミス
1high影響する配点: 1Introductory Organic Chemistry and Alkanes
Drawing a curly arrow starting directly from a negative charge symbol or from the nucleophile atom itself, instead of originating from a lone pair of electrons or a bond.
回避方法: Always draw the lone pair of electrons explicitly on the nucleophile (e.g., on the carbon of CN-, oxygen of OH-, or nitrogen of NH3) and start the tail of your curly arrow precisely on that lone pair.
2high影響する配点: 2Organic Chemistry: Alcohols, Halogenoalkanes and Spectra
Stating that branching weakens covalent bonds when explaining the differences in boiling points of isomeric organic compounds.
回避方法: Explicitly state that branching decreases the surface area of contact between molecules, reducing the strength of intermolecular (London) forces. No covalent bonds are broken during boiling.
3medium影響する配点: 1Organic Chemistry: Carbonyls, Carboxylic Acids and Chirality
Defining the optical activity of chiral molecules as simply rotating 'light' instead of rotating the 'plane of plane-polarised light'.
回避方法: Always use the complete phrase: 'rotates the plane of plane-polarised light' to secure the marks.
4medium影響する配点: 2Organic Synthesis
Failing to draw a flat, horizontal line representing the filter paper on the porous plate, or omitting the label for the vacuum line, in vacuum (Büchner) filtration diagrams.
回避方法: Draw a clear, horizontal line directly touching the porous base inside the Büchner funnel to show the filter paper is flat, and label the connection to the 'vacuum pump' or 'water aspirator' on the side arm of the flask.
5high影響する配点: 2Formulae, Equations and Amount of Substance
Using volume in dm³ or cm³ and pressure in kPa directly in the ideal gas equation (pV = nRT) without converting them to SI units.
回避方法: Always convert volume to m³ (divide dm³ by 1000, or cm³ by 10^6), pressure to Pa (multiply kPa by 1000), and temperature to Kelvin (°C + 273.15) before substituting.
6medium影響する配点: 1Energetics
Forgetting to double the absolute uncertainty of a thermometer when calculating the percentage uncertainty of a temperature change in calorimeters.
回避方法: Since a temperature change (ΔT) is calculated from two individual readings (initial and final), double the thermometer uncertainty (e.g., 2 × ±0.5°C = ±1.0°C) before dividing by ΔT.