Cambridge AS & A Level Chemistry 9701/12 is the May/June 2026 Paper 1 (Multiple Choice), variant 2. It has 40 questions worth one mark each, lasts 1 hour 15 minutes and tests the AS content. Organic chemistry was the biggest area, with 15 questions, and seven questions needed a numerical calculation, from an empirical formula to a nitrile yield. This guide gives the official answer for every question, the topic it tested and the working for each calculation. The paper and its mark scheme are free on the Tutopiya Learning Portal.

For an overview of all five 9701 papers from this series, see A Level Chemistry 9701 May/June 2026 past papers: what came up and how it was marked.

9701/12 at a glance

Syllabus area	Questions	Number of questions
Atoms, moles and stoichiometry	1–4, 8, 40	6
Chemical bonding	5–7	3
Chemical energetics	9–10	2
Redox	11–12	2
Equilibria	13–14	2
Reaction kinetics	15	1
Period 3	16, 17, 19	3
Group 2	20–21	2
Group 17	22–23	2
Nitrogen and sulfur	18, 24	2
Organic chemistry	25–39	15
Total		40

Each correct answer scores one mark, so the total is 40. The paper prints the Periodic Table and the important constants, including R = 8.31 J K⁻¹ mol⁻¹ and a molar gas volume of 24.0 dm³ mol⁻¹ at room conditions.

Answer key and topic for every question

Question	What it tested	Answer
1	Mass of aluminium needed for 0.10 mol of Al₂Cl₆	C
2	Empirical formula from combustion masses	C
3	Neutrons and electrons in a sulfide ion	D
4	Factors explaining a higher first ionisation energy	D
5	Substance with only London dispersion forces	B
6	Orbital overlaps in the bonds of HCN	B
7	Identification key for giant lattice structures	B
8	Volume of nitrogen from the ideal gas equation	B
9	Enthalpy change of formation of NO from an energy cycle	D
10	Enthalpy change of neutralisation from a temperature rise	C
11	Oxidation number of titanium in FeTiO₃ and TiO₂	D
12	Oxidising and reducing agents in making copper(I) iodide	C
13	Equilibrium amount of N₂O₄	A
14	Change that lowers the pH of aqueous ethanoic acid	C
15	Effect of a catalyst on a Boltzmann distribution	D
16	Properties of the Period 3 elements sodium to phosphorus	D
17	Identifying three Period 3 elements from data	D
18	Nitrogen oxides and the formation of SO₃	A
19	Element whose chloride and oxide neutralise each other	A
20	Volume of oxygen from decomposing calcium nitrate	A
21	Group 2 compounds that give a precipitate when mixed	C
22	Why halogen volatility falls down the group	D
23	Strongest oxidising agent	A
24	Making ammonia from ammonium chloride	A
25	Fewest carbon atoms in a chiral non-cyclic alkane	A
26	First propagation steps for pentane and chlorine	B
27	Carbonyl isomers of C₅H₁₀O and their tests	B
28	Main product of propene with ICl	C
29	Hydrolysis of tertiary halogenoalkanes	A
30	Mass and name of the nitrile from 1-bromopropane	A
31	Reaction that gives ethanol as the major product	C
32	Product of hydrating methylpropene, then oxidising	B
33	Pair told apart by alkaline iodine	A
34	Whether esterification and an acid-carbonate reaction are redox	D
35	Products of hydrolysing an ester-acid with NaOH	B
36	Bond angles in ethanenitrile and its hydrolysis product	D
37	Monomer of the polymer with repeat unit –CH₂C(CH₃)₂–	C
38	Fehling’s test before and after oxidising an aldehyde-alcohol	B
39	Number of C₄ hydrocarbons with two sp² carbons	C
40	Expression for Ar of copper from an alloy’s mass spectrum	C

What the paper tested, topic by topic

Atoms, moles and stoichiometry (Questions 1–4, 8 and 40)

Four of the six involved working, so this group sets the pace for the rest of the paper.

• Reacting masses (Question 1): each Al₂Cl₆ contains two aluminium atoms, so 0.10 mol needs 0.20 mol of Al. That is 0.20 × 27.0 = 5.4 g. Forgetting the factor of 2 gives the 2.7 g distractor.
• Empirical formula (Question 2): carbon = 4.00 ÷ 44.0 = 0.0909 mol (1.09 g). Hydrogen = 2 × (1.63 ÷ 18.0) = 0.181 mol (0.18 g). Oxygen is what is left: 2.00 − 1.09 − 0.18 = 0.73 g, or 0.0455 mol. Dividing by 0.0455 gives C : H : O = 2 : 4 : 1, so C₂H₄O.
• Ideal gas equation (Question 8): nitrogen is N₂, so n = 15.0 ÷ 28.0 = 0.536 mol. Convert to SI units: T = 343 K and p = 192 000 Pa. V = nRT ÷ p = 0.536 × 8.31 × 343 ÷ 192 000 = 7.95 × 10⁻³ m³ = 7.95 dm³. Leaving the temperature in °C gives 1.62 dm³, and using 14.0 for the molar mass of nitrogen gives 15.9 dm³.
• Mass spectrum (Question 40): the alloy also contains gold, which gives the peak at 197. The Ar of copper uses only the copper peaks: (56.36 × 63 + 25.14 × 65) ÷ (56.36 + 25.14). Including 18.50 in the denominator dilutes the copper with gold.
• Sub-atomic particles (Question 3): the sulfide ion with mass number 35 has 35 − 16 = 19 neutrons, and 16 + 2 = 18 electrons.
• Ionisation energy (Question 4): only one student had to be right. Oxygen has a higher first ionisation energy than sulfur, but it has fewer protons; it is its smaller radius that explains the difference. So student 2 is right and student 1 is wrong. Carbon and boron make both students right, magnesium and aluminium make both wrong, and oxygen’s first ionisation energy is lower than nitrogen’s, not higher.

Chemical bonding (Questions 5–7)

• Intermolecular forces (Question 5): helium atoms have no permanent dipole, so instantaneous dipole-induced dipole forces are all they have. The other three are polar, and water also forms hydrogen bonds.
• Orbital overlap (Question 6): the C≡N triple bond is one σ bond from two sp hybrid orbitals and two π bonds from p orbitals. The C–H bond uses hydrogen’s s orbital with an sp orbital, so no bond is an overlap of two s orbitals. Answer: 1 and 2 only.
• Giant lattices (Question 7): a compound whose melt conducts is ionic (structure 1). A compound whose melt does not conduct, or an element without ions, is giant covalent (structure 2). An element that contains ions is metallic (structure 3).

Chemical energetics, redox, equilibria and kinetics (Questions 9–15)

• Energy cycle (Question 9): the enthalpy change of formation of NO is ΔH₂, the arrow from the elements. Going the other way round the cycle gives ΔH₂ = ΔH₃ − ΔH₁.
• Neutralisation (Question 10): the solution has a mass of 100 g, because both volumes count, and the amount of acid is 0.050 × 2.5 = 0.125 mol. So ΔH = −(100 × 4.2 × 17) ÷ (0.050 × 2.5) J mol⁻¹. Using only 50 g is the trap in option A.
• Equilibrium amounts (Question 13): 3.0 − 2.3 = 0.70 mol of NO₂ reacted, and two NO₂ make one N₂O₄, so there is 0.35 mol of N₂O₄. Forgetting the 2 : 1 ratio gives 0.70 mol.
• Oxidation numbers (Question 11): in FeTiO₃, iron is +2 and the three oxygens are −6, so titanium is +4. It is also +4 in TiO₂, so there is no change.
• Redox roles (Question 12): every copper goes from +2 to +1, so all the copper ions act as oxidising agents. Only half of the iodide ions become I₂, so “all iodide ions” is wrong.
• Shifting an equilibrium (Question 14): the forward reaction is exothermic, so lowering the temperature moves the position to the right, making more H₃O⁺ and lowering the pH. Adding hydroxide or ethanoate ions does the opposite, and a catalyst changes nothing.
• Boltzmann distribution (Question 15): a catalyst does not change the energies of the molecules, so the peak stays the same height. It lowers the activation energy, so the line moves to the left.

Inorganic chemistry (Questions 16–24)

• Gas volume (Question 20): 2Ca(NO₃)₂ → 2CaO + 4NO₂ + O₂. So 0.50 mol of calcium nitrate gives 0.25 mol of O₂, which is 0.25 × 24.0 = 6.0 dm³. The 30.0 dm³ distractor is the volume of all the gas, NO₂ included.
• Period 3 data (Question 17): the element melting at 98 °C that conducts is sodium, the one melting at 650 °C that conducts is magnesium, and the non-conductor melting at 113 °C is sulfur.
• Period 3 trends (Question 16): only sodium oxide gives a solution with a pH above 12. The others fail on detail: sodium chloride simply dissolves rather than being hydrolysed, outer electrons get closer to the nucleus across the period, and sodium to aluminium are metallic while silicon is giant covalent.
• Chloride and oxide (Question 19): aluminium chloride gives an acidic solution in water, and aluminium oxide, being amphoteric, reacts with that acid.
• Sulfur trioxide (Question 18): NO₂ oxidises SO₂ to SO₃ and is reduced to NO, which the excess oxygen turns back into NO₂. If you add NO, the excess oxygen first converts it to NO₂, so both procedures make some SO₃.
• Group 2 solubility (Question 21): magnesium sulfate and barium hydroxide both dissolve, and mixing them gives insoluble barium sulfate. Barium sulfate and magnesium hydroxide would not form clear solutions to start with.
• Group 17 (Questions 22 and 23): volatility falls down the group because London dispersion forces get stronger as the molecules gain electrons. Chlorine is the strongest oxidising agent of the four.
• Ammonia (Question 24): both statements are true. Ammonium chloride gives ammonia when heated with KOH(aq), and the H–N–H angle falls from the tetrahedral NH₄⁺ ion to the pyramidal NH₃ molecule.

Organic chemistry (Questions 25–39)

Fifteen questions, more than a third of the paper. Four of them asked you to count something, so draw the structures rather than doing it in your head.

• Yield (Question 30): KCN adds a carbon, so the product is butanenitrile, not propanenitrile. The Mr of C₃H₇Br is 122.9, so 36.9 g is 0.300 mol. The Mr of C₃H₇CN is 69.0, so 100% would be 20.7 g, and 78.0% of that is 16.2 g. The 28.8 g distractor is 78.0% of the starting mass.
• Counting (Questions 25, 26, 27 and 39):
  • A chiral alkane needs four different groups on one carbon: H, methyl, ethyl and propyl. That is 3-methylhexane, with 7 carbons.
  • Pentane has hydrogens in 3 different environments (on C1, C2 and C3), so three different first propagation steps are possible.
  • C₅H₁₀O has eight carbonyl isomers: five aldehydes (2-methylbutanal counts twice, as a pair of optical isomers) and three ketones. The five aldehydes give a silver mirror with Tollens’ reagent.
  • The C₄ hydrocarbons with one C=C are but-1-ene, cis- and trans-but-2-ene and methylpropene, which makes 4. Forgetting cis/trans isomerism gives 3.
• Addition of ICl (Question 28): iodine is the δ+ end, so it adds to the end carbon and chlorine goes to the middle one, giving CH₃CHClCH₂I.
• SN1 hydrolysis (Question 29): tertiary halogenoalkanes react by SN1, and the slow step breaks the C–X bond. The C–I bond is weaker, so the reaction is faster when X is iodine. The intermediate is a carbocation, not a radical.
• Making and oxidising alcohols (Questions 31, 32 and 38): NaBH₄ reduces ethanal to ethanol. Methylpropene and steam give methylpropan-2-ol, a tertiary alcohol, which acidified KMnO₄ cannot oxidise, so it distils over unchanged. In Question 38, refluxing X with excess dichromate turns its aldehyde group into a carboxylic acid and its secondary alcohol into a ketone, so only X gives a red precipitate with Fehling’s reagent.
• Iodoform test (Question 33): ethanal has a CH₃CO group and propanal does not. Every other pair gives the same result for both compounds.
• Acids and hydrolysis (Questions 34–36): esterification and the reaction with sodium carbonate involve no change in oxidation numbers, so neither is redox. Excess NaOH hydrolyses the ester in Z and also neutralises its acid group, giving CH₃CO₂⁻Na⁺ and HOCH₂CH₂CO₂⁻Na⁺. In Question 36 the C–C≡N unit is linear (180°), and hydrolysis gives sodium ethanoate, where the C–C–O angle is 120°.
• Polymers (Question 37): the repeat unit –CH₂C(CH₃)₂– comes from CH₂=C(CH₃)₂, methylpropene.

Where the marks are on 9701/12

• Organic chemistry carried 15 marks, more than any other area. Questions 25 to 39 run in one block, so a weak organic topic costs several marks in a row.
• Physical chemistry carried 16 marks: atoms and moles (6), bonding (3), energetics (2), redox (2), equilibria (2) and kinetics (1).
• Inorganic chemistry carried 9 marks: Period 3 (3), Group 2 (2), Group 17 (2) and nitrogen and sulfur (2).
• Seven questions needed a numerical answer: 1, 2, 8, 10, 13, 20 and 30. Questions 9 and 40 asked you to pick an expression, which takes the same care.
• Unit and ratio traps were built into the wrong answers: °C instead of K and N instead of N₂ in Question 8, 50 g instead of 100 g in Question 10, the 2 : 1 ratio in Questions 1 and 13, and the starting mass in Question 30.

How to self-mark 9701/12 with the mark scheme

1. Check each answer against the key above or the official mark scheme. Count one mark per correct letter.
2. Tag every wrong answer by syllabus area, using the at-a-glance table, to see which topic is costing the most.
3. Tag it by reason too: knowledge (for example, not knowing that tertiary alcohols resist oxidation), misread (missing “only one” in Question 4 or “least number” in Question 25) or calculation (a unit or ratio slip in Questions 1, 8, 10 or 13).
4. Redo every calculation you got wrong in full: write the equation, convert the units, then substitute.
5. Redraw the structures for every counting question you missed (25, 26, 27 and 39), listing each isomer, until your count matches.

Sit 9701/12 as a timed mock

You have 75 minutes for 40 questions, just under two minutes each. Use two passes: answer the recall questions first, mark any that need a calculation or a drawn structure, then come back to them.

Block	Questions	Time
Atoms, bonding and the gas calculation	1–8	14 minutes
Energetics, redox, equilibria and kinetics	9–15	11 minutes
Inorganic chemistry	16–24	13 minutes
Organic: isomers, mechanisms and the yield	25–32	17 minutes
Organic: tests and hydrolysis, plus the mass spectrum	33–40	12 minutes
Second pass and check the answer sheet	–	8 minutes

The fourth block is the longest because it holds the three counting questions (25, 26 and 27) and the nitrile yield in Question 30.

Other May/June 2026 9701 papers

• 9701 Paper 22 (AS Level Structured Questions)
• 9701 Paper 32 (Advanced Practical Skills)
• 9701 Paper 42 (A Level Structured Questions)
• 9701 Paper 52 (Planning, Analysis and Evaluation)

Practise and download

• Download 9701/12 and its mark scheme on the Learning Portal →
• All 9701 May/June 2026 papers: overview and marking patterns
• Try a free A Level Chemistry quiz

Need help with a 9701 topic? Book a free trial lesson with an A Level Chemistry tutor →

Frequently asked questions

What topics were on 9701 Paper 12 May/June 2026? +

All of the AS content. Organic chemistry had 15 of the 40 questions. Atoms, moles and stoichiometry had 6, bonding 3, the Period 3 elements 3, and energetics, redox, equilibria, Group 2, Group 17 and nitrogen and sulfur had 2 each. Reaction kinetics had 1.

How many marks is 9701/12 and how long is it? +

It has 40 multiple choice questions, one mark each, for a total of 40 marks. You have 1 hour 15 minutes and you may use a calculator. The Periodic Table and a list of constants are printed in the paper.

Is 9701/12 an AS or A Level paper? +

Paper 1 tests the AS content. It is sat by AS candidates with Papers 2 and 3, and by full A Level candidates, who also take Papers 4 and 5.

What was the answer to the ideal gas question on 9701/12? +

B, 7.95 dm³. Nitrogen is N₂, so 15.0 g is 15.0 ÷ 28.0 = 0.536 mol. Then V = nRT ÷ p = 0.536 × 8.31 × 343 ÷ 192 000 = 7.95 × 10⁻³ m³, which is 7.95 dm³.

How many questions on 9701/12 2026 needed a calculation? +

Seven needed a numerical answer: Questions 1, 2, 8, 10, 13, 20 and 30. Two more, Questions 9 and 40, asked you to pick the right expression, and four organic questions (25, 26, 27 and 39) asked you to count isomers or reaction steps.

Where can I download 9701/12 May/June 2026 and its mark scheme? +

Both are free to download and print on the Tutopiya Learning Portal, on the Cambridge AS & A Level Chemistry 9701 past papers page.

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