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A-Level Chemistry Past Papers & Drilling (Paper 2): Moles, Titration, Organic
TUTORZONE ORIGINAL DRILLING MOCK · CAMBRIDGE A-LEVEL CHEMISTRY (9701) PAPER 2
Written to the Cambridge 9701 syllabus (2025-2027): Paper 2 (AS Level structured questions) is 60 marks over 1 h 15 min, 46% of the AS Level and 23% of the A Level. This is a Paper 2 drilling mock: 8 questions for 60 marks (moles, titration, atomic structure, energetics, equilibrium, inorganic, organic, kinetics) with answers.
What is in A-Level Chemistry (9701) Paper 2?
Direct answer: Paper 2 AS structured questions, 60 marks, 1 h 15 min, 46% of the AS Level and 23% of the A Level. It tests AS content: moles and stoichiometry, atomic structure, bonding, energetics, equilibria, kinetics, inorganic and organic chemistry.
Assessment at a glance (2027)
| Component | Content | Weighting | Duration |
|---|---|---|---|
| Paper 2 (AS structured questions) | Structured questions, 60 marks | AS 46% / A Level 23% | 1 h 15 min |
| Paper 1 (AS multiple choice) | 40 multiple-choice questions, 40 marks | AS 31% / A Level 15.5% | 1 h 15 min |
| Paper 3 (AS practical skills) | Practical work and structured questions, 40 marks | AS 23% / A Level 11.5% | 2 h |
| Paper 4/5 (A2 level) | A2 structured 100 + planning 30 | A Level 38.5% / 11.5% | 2 h / 1 h 15 min |
Eight questions for 60 marks in 1 h 15 min is about 8 minutes each. For calculations write the equation and formula first (n = m/M, c = n/V, q = mcT, Kc), then substitute, then give the unit; for explanations give the cause and then the consequence.
How this paper was built
This is a TutorZone original drilling mock: the questions follow the Cambridge 9701 structure (Paper 2 AS structured questions, 60 marks, 1 h 15 min, 46% of AS) and the answers are our own, not Cambridge past papers or marking references.
Every numerical answer was recomputed programmatically (moles, concentration, relative atomic mass, bond-enthalpy change, Kc).
Pacing
| Section | Marks | Suggested time | What to do first |
|---|---|---|---|
| Paper 2 (AS structured questions) | AS 46% / A Level 23% | about 8 min a question, 8 to check | equation and formula first, then numbers |
| Paper 1 (AS multiple choice) | AS 31% / A Level 15.5% | about 1.9 min a question | speed paper, sweep every question once |
| Paper 3 (AS practical skills) | AS 23% / A Level 11.5% | about 30 min a part | readings, sig figs, uncertainty |
| Paper 4/5 (A2 level) | A Level 38.5% / 11.5% | A2 route only | solid AS base first |
How is Paper 2 different from Paper 4?
Direct answer: Paper 2 covers AS content only – 60 marks, 1 h 15 min, 46% of the AS Level. Paper 4 is the A2 structured paper – 100 marks, 2 hours, 38.5% of the A Level.
Paper 2: AS structured drilling (8 questions, 60 marks)
Four physical-chemistry questions (32 marks) and four inorganic/organic/kinetics questions (28 marks); answer every question.
Question 1 (8 marks)
Magnesium reacts with excess dilute hydrochloric acid: Mg + 2HCl to MgCl2 + H2. 4.80 g of magnesium (Ar = 24.0) reacts completely and the hydrogen is collected at room temperature and pressure (molar volume 24 dm^3/mol).
(a) Calculate the moles of magnesium.
(b) Calculate the moles of hydrogen formed.
(c) Calculate the volume of hydrogen.
Question 2 (8 marks)
25.0 cm^3 of 0.100 mol/dm^3 sodium hydroxide solution is exactly neutralised by 20.0 cm^3 of dilute hydrochloric acid (1:1 reaction).
(a) Calculate the moles of sodium hydroxide.
(b) Calculate the moles of acid used.
(c) Calculate the concentration of the acid.
Question 3 (8 marks)
(a) Write the electron configuration of the atom with 13 protons (aluminium).
(b) How many unpaired electrons does this atom have?
(c) An element has two isotopes: 69.2% with mass number 63 and 30.8% with mass number 65. Calculate its relative atomic mass to three significant figures.
Question 4 (8 marks)
(a) 100 g of water (specific heat capacity 4.18 J/(g degC)) rises by 20.0 degC. Calculate the energy absorbed in kJ.
(b) Use bond energies to calculate the enthalpy change of H2(g) + Cl2(g) to 2HCl(g): H-H = 436, Cl-Cl = 243, H-Cl = 432 kJ/mol.
Question 5 (7 marks)
In a 1 dm^3 vessel, H2(g) + I2(g) <=> 2HI(g) reaches equilibrium with [H2] = 0.10, [I2] = 0.10 and [HI] = 0.60 mol/dm^3.
(a) Write the expression for Kc.
(b) Calculate Kc.
(c) State the factor that changes Kc.
Question 6 (7 marks)
(a) Explain why the reactivity of Group 2 metals with water increases down the group.
(b) State how the thermal stability of Group 2 carbonates changes down the group.
(c) Explain why the oxidising power of Group 17 elements (the halogens) decreases down the group.
Question 7 (7 marks)
(a) Define structural isomerism and give three types.
(b) Write the equation for the addition polymerisation of ethene to poly(ethene) and state the conditions needed.
(c) What are the products when bromoethane is heated with aqueous potassium hydroxide, and with ethanolic potassium hydroxide?
Question 8 (7 marks)
(a) Use activation energy to explain how a catalyst increases the rate of a reaction.
(b) Give two ways to follow the rate of Mg + 2HCl to MgCl2 + H2.
(c) Explain why a catalyst does not change the position of equilibrium.
How many questions and marks does this paper have?
Direct answer: 8 questions for 60 marks, each with a full worked answer; every numerical value was recomputed programmatically.
Paper 2 answers (Questions 1-8)
Question 1
(a) n = m / M = 4.80 / 24.0 = 0.200 mol (3).
(b) 1:1 ratio, so hydrogen = 0.200 mol (2).
(c) V = n x 24 = 0.200 x 24 = 4.8 dm^3 (3).
Question 2
(a) 25.0 cm^3 = 0.0250 dm^3, n = 0.100 x 0.0250 = 0.00250 mol (3).
(b) 1:1, so acid = 0.00250 mol (2).
(c) 20.0 cm^3 = 0.0200 dm^3, c = 0.00250 / 0.0200 = 0.125 mol/dm^3 (3).
Question 3
(a) 1s2 2s2 2p6 3s2 3p1 (3).
(b) The 3p subshell holds one electron, so 1 unpaired electron (2).
(c) Ar = 0.692 x 63 + 0.308 x 65 = 43.596 + 20.020 = 63.6 (3).
Question 4
(a) q = mcT = 100 x 4.18 x 20.0 = 8360 J = 8.36 kJ (3).
(b) Enthalpy = bonds broken – bonds formed = (436 + 243) – 2 x 432 = 679 – 864 = -185 kJ/mol (5).
Question 5
(a) Kc = [HI]^2 / ([H2] x [I2]) (2).
(b) Kc = 0.60^2 / (0.10 x 0.10) = 0.36 / 0.010 = 36 (3).
(c) Kc is changed only by temperature; changing concentration or pressure does not (2).
Question 6
(a) Down the group the atomic radius rises and the outer electron is further from the nucleus, so the first ionisation energy falls and the metal loses its outer electron more easily (3).
(b) It increases: the larger cation polarises the carbonate ion less (2).
(c) The atomic radius rises and the ability to gain an electron falls, so the oxidising power decreases (2).
Question 7
(a) Compounds with the same molecular formula but different atom-to-atom connections; chain, position and functional-group isomerism (3).
(b) n CH2=CH2 to -(CH2-CH2)n-; a catalyst with high temperature and pressure (2).
(c) Aqueous: nucleophilic substitution gives ethanol. Ethanolic: elimination gives ethene (2).
Question 8
(a) The catalyst provides an alternative route with a lower activation energy, so more molecules have enough energy and the frequency of successful collisions rises (3).
(b) (1) measure the volume of hydrogen with a gas syringe over time; (2) measure the loss in mass of magnesium on a balance (2).
(c) It lowers the activation energy of the forward and the reverse reaction by the same amount, so both rates rise equally and the equilibrium position is unchanged (2).
How do I work out moles and concentration in a titration?
Direct answer: divide cm^3 by 1000 to get dm^3, use n = c x V for moles, convert with the equation ratio, then c = n / V for the concentration.
Where these marks are usually lost
| Mistake | What it looks like | What it costs | Instead |
|---|---|---|---|
| Missing units | The number only | Loses every value mark | Add mol, dm^3, mol/dm^3 |
| cm^3 not converted | 25.0 multiplied by 0.100 directly | Concentration out by 1000x | 25.0 cm^3 = 0.0250 dm^3 |
| Wrong molar volume | 22.4 dm^3 used at r.t.p. | Gas volume all wrong | Use 24 dm^3/mol at room temperature |
| Bond energy not scaled | Subtracting 432 only once | Wrong sign and value | 2 mol HCl formed, so multiply by 2 |
| Conclusion only | ‘Because it is more reactive’ | Half marks at best | Give the cause (ionisation energy falls), then the effect |
How to use this paper
First drill: the full 1 h 15 min on all 8 questions with no notes.
Mark it: check every unit and significant figure, and check that each explanation gives both cause and consequence.
Second drill: redo three to seven days later, aiming to finish inside 1 hour; only then move on to the A2 Paper 4.
What should I do after drilling this paper?
Direct answer: log every question where a unit was missing or a coefficient was not scaled; redo the paper in three to seven days; then drill the A2 Paper 4 and Paper 1 multiple choice.
FAQ
Is this a Cambridge past paper?
No. The questions and answers are TutorZone originals, not Cambridge past papers or marking references.
What does A-Level Chemistry Paper 2 test?
AS Level structured questions: moles and stoichiometry, atomic structure, bonding, states of matter, energetics, electrochemistry, equilibria, kinetics, the Periodic Table, Group 2, Group 17 and organic chemistry, 60 marks in 1 h 15 min.
How is Paper 2 different from Paper 4?
Paper 2 covers AS content only: 60 marks, 1 h 15 min, 46% of the AS Level. Paper 4 is the A2 structured paper: 100 marks, 2 hours, 38.5% of the A Level.
Official references
| Resource | What to check |
|---|---|
| Cambridge A-Level Chemistry 9701 programme page | Confirm the marks, times and weightings of Papers 1-5 |
| https://www.tutorzone.com.hk/en-alevel-chemistry-9701-paper-4-mock-2027/ | A-Level Chemistry Paper 4 (A2 structured) drilling mock |
Related: practice area · A-Level Chemistry Paper 4 drilling mock · A-Level Chemistry 9701 drilling guide
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