Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
An energy cycle for the combustion of methane is shown. [Figure showing energy cycle for combustion of methane] Which expressions can be used to ca...
Many gases do not obey the general gas equation at high pressures. Why is this? 1 At higher pressures the molecules have more energy. 2 At higher p...
Which species can accept a lone pair of electrons to form a coordinate (dative covalent) bond? 1 BF₃ 2 H⁺ 3 CH₃⁺
A sample containing x mol of Al₂Cl₆ is dissolved in water to give solution W. In order to precipitate all of the aluminium as its hydroxide, y mol ...
Nitrogen dioxide gas is produced when petrol is burned in car engines. Which acids are made in the atmosphere as a result of this release of nitrog...
In which reactions is the major product formed by a nucleophilic substitution reaction? 1 bromoethane + potassium cyanide in ethanol 2 bromoethane ...
An excess of P reacts with Q, in the presence of concentrated sulfuric acid, to form R. Effervescence is seen when a piece of sodium is added to pu...
Two carbonyl compounds have the molecular formula C₃H₆O. Which reagents give different observations with these two compounds? 1 acidified aqueous p...
An organic compound, T, does not fizz when aqueous sodium carbonate is added to it. Compound T contains 27.6% by mass of oxygen. What could be the ...
The rate of chemical reactions is affected by changes in temperature and pressure.
Chlorine, Cl₂, is a reactive yellow-green gas. It is a strong oxidising agent.
Compounds P, Q and R have all been found in the atmosphere of one of Saturn's moons. P N≡C—C≡C—C≡N Q H—C≡C—C≡N R H | H—C—C≡N | H...
Hydroxyethanal, HOCH₂CHO, has been observed in dust clouds near the centre of our galaxy. [Figure 4.hydroxyethanal_structure]
In this experiment you will carry out a titration to identify the Group 1 metal, M, present in a metal hydrogencarbonate, MHCO3. FA 1 is 0.0550 mo...
In this experiment you will determine the relative formula mass of the same metal hydrogencarbonate, MHCO3, by thermal decomposition. Then you will...
Iron(II) compounds are generally only stable in neutral, non-oxidising conditions. It is difficult to determine the lattice energy of FeO experimen...
Iodates are compounds that contain the IO3¯ anion.
The transition elements are able to form stable complexes with a wide range of molecules and ions.
Carboplatin and satraplatin are used as anticancer drugs instead of cisplatin. [Figure 5.1]
Fumaric acid is a naturally occurring dicarboxylic acid. [Figure 6.1]
Proline (Pro) is a naturally occurring amino acid. [Figure 7.1]
Zinc metal reacts with aqueous copper(II) sulfate. Zn(s) + CuSO₄(aq) → Cu(s) + ZnSO₄(aq) The enthalpy change of this reaction, ΔΗ, can be determine...
Ethanedioic acid is a white crystalline solid. If excess aqueous potassium hydroxide, KOH(aq), is added to dilute ethanedioic acid, H₂C₂O₄(aq), ful...
The first ionisation energy of potassium, K, is 418 kJ mol⁻¹. The first ionisation energy of strontium, Sr, is 548 kJ mol⁻¹. Which statement helps ...
What is the electronic configuration of Mg²⁺?
Compound X contains the elements C, H and O only. 2.00 g of X produces 4.00 g of carbon dioxide and 1.63 g of water when completely combusted. What...
For which molecule is the dipole moment zero?
Which dot-and-cross diagram is correct for Al₂Cl₆? [Figure 5.1]
The boiling points of some hydrogen halides are shown. [Figure 6.1] What is the explanation for the trend in boiling point for the hydrogen halides...
Elements X, Y and Z are all in the first two periods of the Periodic Table. Their Pauling electronegativity values, EN, are shown. [Figure 7.1] Sub...
The equation for reaction 1 is shown. reaction 1 C₆H₁₂O₆ → 2CO₂ + 2C₂H₅OH ΔH/kJ mol⁻¹ C₆H₁₂O₆ a C₂H₅OH b What is the correct expression for the ent...
Nitrogen monoxide is an atmospheric pollutant that is formed inside car engines by an endothermic reaction between nitrogen and oxygen. N₂(g) + O₂(...
Two half-equations are shown. MnO₄⁻ + 2H₂O + 3e⁻ → MnO₂(s) + 4OH⁻ 2OH⁻ + SO₃²⁻ → SO₄²⁻ + H₂O + 2e⁻ The equation for the reaction between manganate(...
Hydrogen peroxide, H₂O₂, decomposes to form water and oxygen. The reaction is catalysed by bromide ions. step 1 2Br⁻(aq) + H₂O₂(aq) + 2H⁺(aq) → 2H₂...
Hydrogen and iodine react to form hydrogen iodide in an exothermic reaction. The equation is shown. H₂(g) + I₂(g) ⇌ 2HI(g) A 1 m³ reaction vessel c...
Diethylzinc, (C₂H₅)₂Zn, is added to NaOH(aq). Two reactions occur. reaction 1 (C₂H₅)₂Zn + H₂O → ZnO + 2C₂H₆ reaction 2 H₂O + ZnO + 2OH⁻ → Zn(OH)₄²⁻...
Which statement about atoms and molecules is correct?
The Boltzmann distribution for one mole of a gas at temperature T is shown. [Figure 15.1] One mole of the same gas is added, and the gas remains at...
In the reaction shown, the concentrations of both X and Y are reduced to half of their original values whilst keeping the total volume of the solut...
A student investigated the chloride of a Period 3 element. This is what the student wrote down as a record. "The compound was a white crystalline s...
The elements in Period 3 and their compounds show trends across the period from sodium to chlorine. Which row is correct? [Figure 18.1]
The table shows the melting points of SiO₂ and P₄O₆. [Figure 19.1] Which statement explains the difference between the melting points of SiO₂ and P...
Equal masses of CaCO₃, Ca(NO₃)₂, BaCO₃ and Ba(NO₃)₂ are thermally decomposed. The volume of gas produced in each experiment is measured under the s...
Which row gives correct comparisons between the solubilities of calcium hydroxide and barium hydroxide and the thermal stabilities of calcium carbo...
Which statement relating to the elements in Group 17 and their compounds is correct?
An excess of chlorine was bubbled into 100 cm³ of hot 6.0 mol dm⁻³ sodium hydroxide. How many moles of sodium chloride would be produced in the rea...
The product of the Contact process is Z. Which reaction or process leads to the formation of a gas that can neutralise an aqueous solution of Z?
When ammonia, NH₃, is dissolved in water, a small concentration of ammonium ions, NH₄⁺, is formed. Which row is correct? [Figure 25.1]
In this question, alkenes and cyclic alkanes should be considered. How many structural isomers of C₄H₈ are there?