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.
อ่าน 4 นาทีอัปเดตเมื่อ: 21 มิ.ย. 2569
ภาพรวมข้อสอบ
จำนวนฉบับ
6
คะแนนเต็ม
440
เวลาสอบ
9ชม. 10นาที
ประเภทคำถาม
4
ฉบับ
เวลา
คะแนน
จำนวนข้อ
น้ำหนักคะแนน
ประเภทคำถาม
Unit 1: Structure, Bonding and Introduction to Organic Chemistry
1ชม. 30นาที
80
35
40%
Multiple Choice, Short Answer / Calculation
Unit 2: Energetics, Group Chemistry, Halogenoalkanes and Alcohols
1ชม. 30นาที
80
33
40%
Multiple Choice, Short Answer / Calculation, Extended Writing (Level of Response)
Unit 3: Practical Skills in Chemistry I
1ชม. 20นาที
50
4
20%
Practical Analysis / Graphing / Calculation
Unit 4: Rates, Equilibria and Further Organic Chemistry
1ชม. 45นาที
90
39
40%
Multiple Choice, Short Answer / Calculation, Extended Writing (Level of Response)
Unit 5: Transition Metals and Organic Nitrogen Chemistry
1ชม. 45นาที
90
39
40%
Multiple Choice, Short Answer / Calculation, Extended Writing (Level of Response)
Unit 6: Practical Skills in Chemistry II
1ชม. 20นาที
50
4
20%
Practical Analysis / Graphing / Calculation
เกณฑ์เกรด
A*ABCDEU
ข้อกำหนดเครื่องคิดเลข
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%)
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, 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)
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, 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)
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, 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)
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, but clear stored programs/data (graphical calculators in exam mode) and show the required working — unsupported calculator answers score no method marks.
ข้อผิดพลาดที่พบบ่อย
1highคะแนนที่เกี่ยวข้อง: 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.
วิธีหลีกเลี่ยง: 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.
2highคะแนนที่เกี่ยวข้อง: 2Organic Chemistry: Alcohols, Halogenoalkanes and Spectra
Stating that branching weakens covalent bonds when explaining the differences in boiling points of isomeric organic compounds.
วิธีหลีกเลี่ยง: 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.
3mediumคะแนนที่เกี่ยวข้อง: 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'.
วิธีหลีกเลี่ยง: Always use the complete phrase: 'rotates the plane of plane-polarised light' to secure the marks.
4mediumคะแนนที่เกี่ยวข้อง: 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.
วิธีหลีกเลี่ยง: 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.
5highคะแนนที่เกี่ยวข้อง: 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.
วิธีหลีกเลี่ยง: 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.
6mediumคะแนนที่เกี่ยวข้อง: 1Energetics
Forgetting to double the absolute uncertainty of a thermometer when calculating the percentage uncertainty of a temperature change in calorimeters.
วิธีหลีกเลี่ยง: 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.