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.
阅读时间 5 分钟更新于: 2026年6月21日
试卷概览
卷数
2
总分
140
考试时间
3小时
题型
3
试卷
时间
分数
题数
比重
题型
Foundations of chemistry
1小时 30分钟
70
24
50%
選擇題, Structured/Short Answer
Chemistry in depth
1小时 30分钟
70
6
50%
Structured/Short Answer, Level of Response (LOR)
评级
ABCDEU
计算器规定
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%)
根据历届试题与评分标准整理（2022–2024）。
计算器程序
Graph: zeros, intersections & turning points
Graphical calculator / GDC (exam mode)
用途: Plot a function to read its roots (zeros), points of intersection, and maxima/minima.
使用时机: Checking solutions, sketching, or solving where an analytic method is hard.
步骤
Graph the function(s) and use the built-in zero, intersect and maximum/minimum tools.
考试提示: 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)
用途: Solve an equation or find a variable numerically when an algebraic route is long or implicit.
使用时机: Iterative or implicit equations, or to confirm an algebraic solution.
步骤
Use the equation/zero solver, entering the equation and a sensible starting estimate.
考试提示: 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)
用途: Evaluate a definite integral \(\int_a^b f(x)\,dx\) or a gradient \(f'(x)\) at a point.
使用时机: Checking calculus answers, or where only a numerical value is needed.
步骤
Use the GDC's numeric integral / derivative function with the limits or the point.
考试提示: 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)
用途: 1-var/2-var statistics, linear regression, and cumulative binomial / normal / Poisson probabilities without tables.
使用时机: Statistics questions and hypothesis tests.
步骤
Enter data in the statistics editor, or use the distribution menu (binomial cdf, normal cdf, …).
考试提示: 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.
常见错误
1high涉及分数: 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).
如何避免: Always include the charge sign (+ or -) explicitly prefixing the number when assigning formal oxidation states.
2high涉及分数: 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.
如何避免: 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.
如何避免: 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涉及分数: 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).
如何避免: Describe the physical changes observed, such as: 'the white solid disappears to form a clear, colourless solution'.
5medium涉及分数: 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.
如何避免: 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涉及分数: 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.
如何避免: Use single-headed fishhook arrows originating directly from the middle of the breaking covalent bond pointing to each of the respective atoms.
7high涉及分数: 1Energetics (Developing fuels (DF))
Omitting the negative (-) sign for exothermic enthalpy values in final calculated energetics answers.
如何避免: 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涉及分数: 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.
如何避免: 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.