Practise 619 real Chemistry questions from 2021 to 2026. See the correct answer and a clear explanation the moment you answer.
O Level Chemistry (Cambridge (CAIE) 5070) is examined in the May/June and Oct/Nov series. Tayyari Karo has real questions from 2021 to 2026 across Paper 1, Paper 2, Paper 3, Paper 4, covering topics such as Organic, Bonding, Electrolysis, Moles and Tests. The fastest way to improve is to work through real questions and read why each answer is right.
Tayyari Karo collects the real Cambridge (CAIE) Chemistry questions in one place, sorted by paper and topic. 440 of them are multiple choice and marked instantly, and the rest are structured questions with a full model answer.
These are real past-paper questions. Think of your answer first, then open the explanation.
A student has to measure 28.2 cm³ of aqueous sodium bromide. Which piece of apparatus should be selected?
Answer: B. B 50 cm³ measuring cylinder
A measuring cylinder reads to 0.1 cm³ and can measure 28.2 cm³.
Which property of a liquid ester can be used to check its purity before use as a food flavouring?
Answer: A. boiling point
A pure substance has a sharp boiling point.
Which sequence separates a pure, dry sample of hydrated copper(II) sulfate from a mixture with calcium carbonate?
Answer: B. dissolve in water then filtration then crystallisation
Dissolve, filter off insoluble CaCO₃, crystallise CuSO₄.
Helium, neon, argon, krypton, xenon and radon are noble gases in Group VIII. (a) Name the noble gas with the greatest volume composition in air. (b) State one use for helium. (c) Radon is very unreactive. Use the electronic structure of radon to explain why. (d) Two isotopes of radon are 220/86Rn and 222/86Rn. (i) Give one similarity in their atomic structure. (ii) Give one difference. (e) Xenon forms a compound with 22.1% O and 17.5% F by mass. Calculate its empirical formula. (f) A 21 dm3 sample of neon is at rtp. (i) Temperature increased, pressure constant: describe and explain the volume change. (ii) Pressure increased, temperature constant: describe and explain. (iii) Calculate the mass of neon in the sample (2 s.f.).
(a) argon. (b) fills balloons/airships (less dense than air, non-flammable) or in breathing mixtures for divers. (c) radon has a full outer shell of electrons (octet), so it has little tendency to gain, lose or share electrons. (d)(i) same number of protons (86) / same electron arrangement. (ii) different number of neutrons (134 vs 136). (e) Xe:O:F moles = 60.4/131 : 22.1/16 : 17.5/19 = 0.461 : 1.38 : 0.921 -> divide by 0.461 = 1 : 3 : 2, so XeO3F2. (f)(i) volume increases (faster particles exert greater pressure, pushing walls out). (ii) volume decreases (particles forced closer). (iii) moles = 21/24 = 0.875; mass = 0.875 x 20 = 17.5 -> 18 g (2 s.f.).
Group VIII elements have complete outer shells; empirical formula from % mass via moles.
Number of questions available for each paper.
| Session | Paper 1 | Paper 2 | Paper 3 | Paper 4 |
|---|---|---|---|---|
| May/June 2026 | 40 | 8 | 3 | 4 |
| May/June 2025 | 40 | 8 | 3 | 4 |
| Oct/Nov 2025 | 40 | 10 | 3 | 4 |
| May/June 2024 | 40 | 9 | 3 | 4 |
| Oct/Nov 2024 | 40 | 7 | 3 | 4 |
| May/June 2023 | 40 | 10 | 3 | 4 |
| Oct/Nov 2023 | 40 | 9 | 3 | 4 |
| May/June 2022 | 40 | 9 | 2 | 5 |
| Oct/Nov 2022 | 40 | 9 | 2 | 7 |
| May/June 2021 | 40 | 9 | 2 | 6 |
| Oct/Nov 2021 | 40 | 10 | 2 | 6 |
Yes. Every question comes from a real Cambridge (CAIE) Chemistry (5070) paper from 2021 to 2026. Each one shows the year, session and paper it came from.
You can start free with no signup. A small set of papers per subject is free, and Premium unlocks every paper, the full question bank and the paper PDFs.
Yes. Every question gives you the correct answer straight away with a short explanation, so you learn from mistakes instead of just marking them.
Paper 1, Paper 2, Paper 3, Paper 4 across the May/June and Oct/Nov sessions. Multiple-choice questions are marked automatically, and structured questions show a full model answer.
