Cambridge IGCSE Chemistry 0620/22 is the May/June 2026 Paper 2 (Extended Multiple Choice), variant 2. It lasts 45 minutes, has 40 questions worth one mark each (40 marks in total) and is sat by every Extended candidate. It covered every syllabus area, with two full calculations (a limiting-reactant gas volume and an NF₃ bond-energy sum) and several questions where the trap is a near-miss of the right idea. The mark scheme is an answer key, so this guide gives every answer with the topic it tested and the chemistry behind it. The paper and its mark scheme are free on the Tutopiya Learning Portal.

For an overview of all six 0620 papers from this series, see IGCSE Chemistry 0620 May/June 2026 past papers: what came up and how it was marked.

0620/22 at a glance

Syllabus area	Questions	Number of questions
States of matter, atoms and bonding	1–7	7
Stoichiometry	8–10	3
Electrochemistry	11–13	3
Chemical energetics, rates, equilibrium and redox	14–18	5
Acids, bases and salts	19–22	4
The Periodic Table	23–24	2
Metals	25–28	4
Chemistry of the environment	29–31	3
Organic chemistry	32–37	6
Experimental techniques and chemical analysis	38–40	3
Total		40

Answer key and topic for every question

Question	What it tested	Answer
1	Particle spacing and motion in ice, water and steam	D
2	Kinetic energy and pressure when a sealed gas cools	A
3	Particle diagram showing a mixture of compounds	C
4	Why water counts as a compound	A
5	Particles with the same chemical properties (isotopes)	B
6	Why sodium chloride has a high melting point	A
7	Structure of an element used as lubricant and cutting tool	A
8	Formulas of iron(II) bromide and zinc nitrate	B
9	Definition of relative molecular mass	A
10	Maximum hydrogen volume with a limiting reactant	B
11	Anode, cathode and electrolyte for silver-plating a spoon	A
12	Anode product when dilute sulfuric acid is electrolysed	B
13	Copper(II) sulfate electrolysis with copper electrodes	D
14	Bond-energy calculation for forming NF₃	B
15	Role of concentrated sulfuric acid in making an ester	D
16	Collision theory explanation for higher concentration	D
17	Raw materials and conditions of the Haber process	D
18	Species oxidised and oxidising agent in a dichromate reaction	C
19	Rate and gas volume with a weak acid instead	D
20	Products of magnesium carbonate with hydrochloric acid	C
21	Apparatus and end point in an acid–alkali titration	C
22	Which pair of solutions gives a precipitate	A
23	Statements about how the Periodic Table is arranged	C
24	Trends in the alkali metals	C
25	Malleability of alloys and the reason for it	B
26	Why aluminium seems unreactive with dilute acid	B
27	Blast furnace equation for reducing hematite	A
28	Redox at the electrodes in aluminium extraction	B
29	Balanced equation for photosynthesis	B
30	What catalytic converters do	C
31	Strategies for cutting global warming and acid rain	C
32	Comparing a branched alkane and an alkene	D
33	Matching a name to a correct condensed structure	C
34	Spotting a substitution reaction	A
35	Alkene that adds bromine to give a given product	C
36	Repeat unit of PET	A
37	Repeat unit of nylon	D
38	Correct set-up for paper chromatography	C
39	Process for making drinking water from sea water	B
40	Ion giving an orange-red flame	D

What the paper tested, topic by topic

States of matter, atoms and bonding (Questions 1–7)

• Ice, water and steam (Q1): particles in a solid still vibrate about fixed positions. The other options have the order wrong: steam particles are furthest apart and fastest, not closest or second fastest.
• Cooling a sealed gas (Q2): at lower temperature the molecules have less kinetic energy, hit the walls less often and less hard, so the pressure falls too.
• Mixture of compounds (Q3): the right diagram contains two different kinds of molecule, each made of two different atoms. One option shows a single compound, and another mixes a compound with elements.
• Water as a compound (Q4): its elements are chemically combined in fixed proportions, so only a chemical change separates them. A compound’s properties differ from those of its elements.
• Isotopes (Q5): W (17 protons, 18 neutrons) and Y (17 protons, 20 neutrons) are atoms of the same element with the same number of electrons, so they react the same way. X and Z have different proton numbers from W and Y.
• Sodium chloride (Q6): a giant ionic lattice held by strong ionic bonds needs a lot of energy to break. Intermolecular forces belong to simple molecular substances.
• Element G (Q7): carbon. Graphite is the lubricant and diamond is used in cutting tools, and both have giant covalent structures.

Stoichiometry (Questions 8–10)

• Formulas (Q8): iron(II) is Fe²⁺ and bromide is Br⁻, giving FeBr₂. Zinc is Zn²⁺ and nitrate is NO₃⁻, giving Zn(NO₃)₂; the brackets are needed because there are two nitrate ions.
• Relative molecular mass (Q9): the sum of the relative atomic masses of the atoms in the molecule. Option D describes relative atomic mass, and option B describes an empirical formula.
• Limiting reactant (Q10): moles of HCl = 0.100 dm³ × 1.0 mol/dm³ = 0.10 mol. The magnesium (0.10 mol) would need 0.20 mol of HCl, so the acid runs out first. 0.10 mol HCl gives 0.05 mol H₂, and 0.05 × 24 = 1.2 dm³. Treating magnesium as limiting gives 2.4 dm³ (C), and stopping at moles gives 0.05 (A).

Electrochemistry (Questions 11–13)

• Silver-plating (Q11): the spoon is the cathode, silver is the anode, and the electrolyte must contain silver ions. Options C and D swap the electrodes.
• Dilute sulfuric acid (Q12): oxygen at the anode, from hydroxide ions or water. Hydrogen forms at the cathode.
• Copper electrodes (Q13): copper dissolves from the anode and deposits on the cathode at the same rate, so the cathode gains mass, the anode loses mass and the blue colour stays the same. With inert electrodes the colour would fade, which is the trap in option C.

Chemical energetics, rates, equilibrium and redox (Questions 14–18)

• Bond energies (Q14): bonds broken = one N≡N + three F–F = 950 + (3 × 150) = 1400 kJ. Bonds made = six N–F (two NF₃, three each) = 6 × 280 = 1680 kJ. Energy change = 1400 − 1680 = −280 kJ/mol. Reversing the sign gives C, and adding the two totals gives D (+3080).
• Esterification (Q15): concentrated sulfuric acid is a catalyst. It is a stronger acid than ethanoic acid, and it does not push the equilibrium to the left.
• Concentration (Q16): there are more particles in the same volume, so more collisions per second. A higher percentage of successful collisions (A and C) is the explanation for raising temperature, not concentration, and activation energy only falls with a catalyst.
• Haber process (Q17): nitrogen comes from the air and hydrogen from methane. Hydrogen is not made from a metal and acid, and the process runs at around 200 atm, not 1 atm.
• Redox (Q18): sulfur dioxide gains oxygen to become sulfate, so it is oxidised. Dichromate(VI) is reduced to Cr³⁺, so it is the oxidising agent. H⁺ does not change oxidation state.

Acids, bases and salts (Questions 19–22)

• Weak acid (Q19): ethanoic acid has a lower H⁺ concentration, so the reaction is slower. The magnesium mass is the same and the acid is in excess, so the total volume is still 70 cm³. Halving the volume (35 cm³) confuses rate with amount.
• Carbonates (Q20): acid + carbonate gives a salt, water and carbon dioxide. Hydrogen only forms when an acid reacts with a metal.
• Titration (Q21): the acid is measured into the flask with a volumetric pipette, the alkali is added dropwise near the end point, and methyl orange changes colour rather than disappearing. “Disappears” fits phenolphthalein, which is the trap in options A and D.
• Precipitation (Q22): ammonium carbonate and calcium sulfate together form insoluble calcium carbonate. The other pairs only make soluble salts, since all ammonium, sodium, potassium and nitrate salts are soluble.

The Periodic Table (Questions 23–24)

• Arrangement (Q23): the table is in order of proton number, and Group II elements form 2+ ions. Horizontal rows are periods, not groups, and elements become less metallic from left to right.
• Alkali metals (Q24): melting point decreases down Group I, so sodium melts higher than potassium. Potassium is more reactive than sodium, lithium is less dense than sodium, and all alkali metals have one outer electron.

Metals (Questions 25–28)

• Alloys (Q25): different-sized atoms disrupt the layers, so they slide less easily and the alloy is less malleable. Option A has the right result with the opposite reason.
• Aluminium’s oxide layer (Q26): aluminium is more reactive than zinc, but a thin layer of aluminium oxide stops the acid reaching the metal. Option C is true but does not explain why aluminium fails to react.
• Blast furnace (Q27): Fe₂O₃ + 3CO → 2Fe + 3CO₂. Hematite is iron(III) oxide, not FeO, and carbon monoxide is the reducing agent.
• Aluminium extraction (Q28): the trap question of the paper. Oxide ions are oxidised at the anode, not reduced. The oxygen produced then reacts with the hot carbon anode to make carbon dioxide, and in that reaction oxygen gas gains electrons, so it is reduced at the anode. Aluminium ions, not oxide ions, are reduced at the cathode.

Chemistry of the environment (Questions 29–31)

• Photosynthesis (Q29): 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. Option D is the reverse (respiration) and option C is fermentation.
• Catalytic converters (Q30): they convert oxides of nitrogen from the engine into nitrogen. Catalysts are not used up, so they do not need regular replacement.
• Global warming and acid rain (Q31): less livestock farming cuts methane, and catalytic converters cut oxides of nitrogen that cause acid rain. Burning more wood and using more coal both make things worse, and low-sulfur fuels tackle acid rain, not global warming.

Organic chemistry (Questions 32–37)

• Two hydrocarbons (Q32): a branched alkane with six carbons (C₆H₁₄) and an alkene with six carbons (C₆H₁₂). They are not isomers, because their formulas differ, and only the alkane is saturated. Both contain six carbon atoms, so complete combustion of the same number of moles gives the same volume of carbon dioxide.
• Names and structures (Q33): only propan-1-ol (CH₃CH₂CH₂OH) is written correctly. Check the number of hydrogens on each carbon in the others: each one breaks the four-bond rule for carbon.
• Substitution (Q34): a chlorine atom replaces a hydrogen atom in chloroethane, and HCl forms. The others are dehydration, combustion and addition.
• Adding bromine (Q35): the product has bromine on carbons 2 and 3, so the double bond was between those carbons: but-2-ene, CH₃CH=CHCH₃. But-1-ene would put bromine on carbons 1 and 2.
• PET (Q36): a polyester, so the repeat unit has ester links (–COO–). Option B has amide links, which is nylon.
• Nylon (Q37): a polyamide, with –CONH– links between the two monomer blocks. Option B is a polyester.

Experimental techniques and chemical analysis (Questions 38–40)

• Chromatography (Q38): the bottom of the paper must dip into the solvent, but the spot of ink must start above the solvent level, otherwise it dissolves into the solvent instead of travelling up the paper. Check each diagram for both: in one the paper does not reach the solvent at all, and in others the spot sits at or below the surface.
• Sea water (Q39): distillation separates the water from the dissolved salt. Filtration cannot remove dissolved substances, and chlorination only kills microbes.
• Flame test (Q40): orange-red is calcium. Lithium is red, copper(II) is blue-green and potassium is lilac.

Where the marks are on 0620/22

• Particles, atoms and bonding (7) and organic chemistry (6) carried 13 of the 40 marks.
• Energetics, rates, equilibrium and redox carried 5 marks, with electrochemistry another 3. Redox reasoning also decided Q28 in the metals section.
• Two questions needed a full calculation: the limiting-reactant gas volume (Q10) and the NF₃ bond energies (Q14). Q19 needed you to reason about a gas volume without calculating, and Q5 needed you to read a table of protons, neutrons and electrons.
• Five questions were built on a diagram (Q3, Q32, Q36, Q37 and Q38), and Q33 asked you to check condensed formulas bond by bond.
• Several questions rewarded a precise reason over a true fact, for example Q25 (right result, wrong reason in option A), Q26 (aluminium is above zinc, but the oxide layer is the explanation) and Q16 (more collisions per second, not a higher percentage of successful ones).

How to self-mark 0620/22

1. Mark against the key only. One mark per question, no partial marks.
2. Tag every wrong answer by topic, using the syllabus areas in the table above.
3. Tag it by reason as well:
   • Knowledge: a fact you did not know, such as the source of hydrogen for the Haber process (Q17) or the calcium flame colour (Q40).
   • Misread: you knew the chemistry but missed a detail, for example picking a statement that is true but does not explain the observation (Q26), or mixing up the cathode and anode columns (Q13).
   • Calculation: you set up the working wrongly, such as treating magnesium as the limiting reactant in Q10, or forgetting that 2NF₃ contains six N–F bonds in Q14.
4. Rework every calculation you got wrong in full, writing each step, before you look at the working above.
5. Redo every wrong question a week later without the key, to check the fix has stuck.

Sit 0620/22 as a timed mock

The paper allows 45 minutes for 40 questions, about one minute each. Use two passes: answer everything you are sure of, flag the calculations and the questions where two options look right, then come back.

Block	Questions	Time
First pass, Questions 1–20	20	17 minutes
First pass, Questions 21–40	20	17 minutes
Second pass: flagged questions, Q10 and Q14	–	8 minutes
Final check: one answer per question on the answer sheet	–	3 minutes

Never leave a question blank. Rule out the options you know are wrong and make your best choice from what is left.

Other May/June 2026 0620 papers

• 0620 Paper 12 (Core Multiple Choice)
• 0620 Paper 32 (Core Theory)
• 0620 Paper 42 (Extended Theory)
• 0620 Paper 52 (Practical Test)
• 0620 Paper 62 (Alternative to Practical)

Practise and download

• Download 0620/22 and its mark scheme on the Learning Portal →
• All 0620 May/June 2026 papers: overview and marking patterns
• Try a free IGCSE Chemistry quiz

Need help with a 0620 topic? Book a free trial lesson with an IGCSE Chemistry tutor →

Frequently asked questions

What topics were on 0620 Paper 22 May/June 2026? +

All ten syllabus areas. Particles, atoms and bonding had seven questions, organic chemistry six, and energy, rates, equilibrium and redox five. The rest covered stoichiometry, electrolysis, acids and salts, the Periodic Table, metals, the environment, and chromatography and tests.

How many marks is 0620/22 and how long is it? +

It has 40 multiple choice questions, one mark each, for a total of 40 marks. It lasts 45 minutes.

What was the answer to the NF3 bond energy question on 0620/22? +

B, −280 kJ/mol. Breaking one N≡N and three F–F bonds takes 950 + 450 = 1400 kJ; making six N–F bonds releases 6 × 280 = 1680 kJ; 1400 − 1680 = −280 kJ/mol.

What was the answer to the hydrogen volume question on 0620/22? +

B, 1.2 dm³. 100 cm³ of 1.0 mol/dm³ acid is 0.10 mol HCl, which is the limiting reactant, so it makes 0.05 mol of hydrogen, and 0.05 × 24 = 1.2 dm³.

Is 0620/22 the Core or Extended paper? +

Extended. Paper 2 is the Extended multiple choice paper, sat alongside Paper 4 (Extended Theory) and either Paper 5 or Paper 6. Core candidates sit Paper 1 instead.

Where can I download 0620/22 May/June 2026 and its mark scheme? +

Both are free to download and print on the Tutopiya Learning Portal, on the Cambridge IGCSE Chemistry 0620 past papers page.

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