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.
อ่าน 5 นาทีอัปเดตเมื่อ: 21 มิ.ย. 2569
ภาพรวมข้อสอบ
จำนวนฉบับ
2
คะแนนเต็ม
140
เวลาสอบ
3ชม.
ประเภทคำถาม
3
ฉบับ
เวลา
คะแนน
จำนวนข้อ
น้ำหนักคะแนน
ประเภทคำถาม
Foundations of chemistry
1ชม. 30นาที
70
24
50%
Multiple Choice, Structured/Short Answer
Chemistry in depth
1ชม. 30นาที
70
6
50%
Structured/Short Answer, Level of Response (LOR)
เกณฑ์เกรด
ABCDEU
ข้อกำหนดเครื่องคิดเลข
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%)
วัตถุประสงค์: Plot a function to read its roots (zeros), points of intersection, and maxima/minima.
ใช้เมื่อใด: Checking solutions, sketching, or solving where an analytic method is hard.
ขั้นตอน
Graph the function(s) and use the built-in zero, intersect and maximum/minimum tools.
ข้อควรระวังในการสอบ: 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)
วัตถุประสงค์: Solve an equation or find a variable numerically when an algebraic route is long or implicit.
ใช้เมื่อใด: Iterative or implicit equations, or to confirm an algebraic solution.
ขั้นตอน
Use the equation/zero solver, entering the equation and a sensible starting estimate.
ข้อควรระวังในการสอบ: 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)
วัตถุประสงค์: Evaluate a definite integral \(\int_a^b f(x)\,dx\) or a gradient \(f'(x)\) at a point.
ใช้เมื่อใด: Checking calculus answers, or where only a numerical value is needed.
ขั้นตอน
Use the GDC's numeric integral / derivative function with the limits or the point.
ข้อควรระวังในการสอบ: 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)
วัตถุประสงค์: 1-var/2-var statistics, linear regression, and cumulative binomial / normal / Poisson probabilities without tables.
ใช้เมื่อใด: Statistics questions and hypothesis tests.
ขั้นตอน
Enter data in the statistics editor, or use the distribution menu (binomial cdf, normal cdf, …).
ข้อควรระวังในการสอบ: 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.
ข้อผิดพลาดที่พบบ่อย
1highคะแนนที่เกี่ยวข้อง: 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).
วิธีหลีกเลี่ยง: Always include the charge sign (+ or -) explicitly prefixing the number when assigning formal oxidation states.
2highคะแนนที่เกี่ยวข้อง: 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.
วิธีหลีกเลี่ยง: 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.
วิธีหลีกเลี่ยง: 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.
4highคะแนนที่เกี่ยวข้อง: 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).
วิธีหลีกเลี่ยง: Describe the physical changes observed, such as: 'the white solid disappears to form a clear, colourless solution'.
5mediumคะแนนที่เกี่ยวข้อง: 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.
วิธีหลีกเลี่ยง: 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.
6mediumคะแนนที่เกี่ยวข้อง: 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.
วิธีหลีกเลี่ยง: Use single-headed fishhook arrows originating directly from the middle of the breaking covalent bond pointing to each of the respective atoms.
Omitting the negative (-) sign for exothermic enthalpy values in final calculated energetics answers.
วิธีหลีกเลี่ยง: 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.
8mediumคะแนนที่เกี่ยวข้อง: 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.
วิธีหลีกเลี่ยง: 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.