An expert analysis and preparation suite for OCR AS Level Chemistry B (Salters) H033, containing an exhaustive study article, high-frequency exam pitfalls with solutions grounded in examiner reports, and a calculator-based numerical solver template.
読了時間 5 分更新日: 2026年6月21日
試験の概要
試験数
2
満点
140
制限時間
3時間
出題形式
3
試験
時間
配点
問題数
配点比率
出題形式
Foundations of chemistry
1時間 30分
70
24
50%
Multiple Choice, Structured/Short Answer
Chemistry in depth
1時間 30分
70
6
50%
Structured/Short Answer, Level of Response (LOR)
評価段階
ABCDEU
電卓の規定
A scientific or graphical calculator that meets JCQ regulations may be used (some GCSE Mathematics and Science papers are non-calculator). Graphical calculators must be set to exam mode; you must clear any stored programs, notes or data before the exam, and the calculator must not be able to retrieve stored text or formulae.
AO1: Knowledge and understanding of scientific ideas, processes, techniques and procedures (35%)
AO2: Apply knowledge and understanding of scientific ideas, processes, techniques and procedures (42%)
AO3: Analyse, interpret and evaluate scientific information, ideas and evidence (23%)
過去問と採点基準にもとづいて作成（2022–2024）。
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 under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
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 under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
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 under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
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 under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
よくあるミス
1high影響する配点: 2Redox (Elements from the sea (ES))
Omitting the necessary '+' signs on positive oxidation numbers (e.g., writing '2' instead of '+2' for sulfur in thiosulfate, or '2.5' instead of '+2.5' for sulfur in tetrathionate).
回避方法: Always include the charge sign (+ or -) explicitly prefixing the number when assigning formal oxidation states.
2high影響する配点: 3Formulae, equations and amount of substance (Developing fuels (DF))
Failing to convert standard units in ideal gas equation calculations, such as using volumes in cm3 instead of m3, or temperature in Celsius instead of Kelvin.
回避方法: Multiply cm3 by 10^-6 to get m3, multiply dm3 by 10^-3 to get m3, and add 273 to any Celsius values before starting calculations.
Drawing curly arrows during mechanisms starting from negative charges (like the minus on an iodide ion) rather than originating directly from the lone pair of electrons.
回避方法: Ensure all nucleophilic curly arrows begin directly on the lone pair of electrons (e.g. :I-) and point directly to the target electron-deficient carbon atom.
4high影響する配点: 2Inorganic chemistry and the periodic table (Elements of life (EL))
Confusing visual observations with theoretical chemical deductions (e.g., stating 'it dissolves' or 'reacts' instead of describing what is physically seen).
回避方法: Describe the physical changes observed, such as: 'the white solid disappears to form a clear, colourless solution'.
5medium影響する配点: 1Formulae, equations and amount of substance (Elements from the sea (ES))
Failing to account for the double uncertainty of standard laboratory balances when weighing by difference.
回避方法: Remember that weighing by difference requires two mass measurements; the absolute uncertainty of a single reading (e.g., 0.005 g) must be multiplied by 2 (0.01 g) before calculating the percentage uncertainty.
6medium影響する配点: 1Reaction mechanisms (The ozone story (OZ))
Incomplete or inaccurate representation of homolytic bond fission, where fishhook arrows are drawn away from the bond or represent full electron pair movement.
回避方法: Use single-headed fishhook arrows originating directly from the middle of the breaking covalent bond pointing to each of the respective atoms.
7high影響する配点: 1Energetics (Developing fuels (DF))
Omitting the negative (-) sign for exothermic enthalpy values in final calculated energetics answers.
回避方法: Once you determine that a reaction is exothermic (e.g., a temperature rise occurred), ensure the final value of delta H is explicitly written with a negative sign.
8medium影響する配点: 2Modern analytical techniques (What's in a medicine? (WM))
Failing to explain the structural significance of the absence of certain bands in infrared spectroscopy questions.
回避方法: When identifying a molecule, explicitly rule out alternative functional groups by stating, for example, that the absence of a broad peak at 2500-3600 cm-1 proves it is not a carboxylic acid.