Cambridge Past Paper Questions

Dinitrogen pentoxide, N2O5, is dissolved in an inert solvent (solv) and the rate of decomposition of N2O5 is investigated. This reaction produces n...

Hydrogen peroxide decomposes slowly at room temperature to give water and oxygen. 2H2O2(aq) → 2H2O(l) + O2(g) The initial rate of this reaction can...

A student is given 250.0 cm³ of solution containing a mixture of Fe2+ and Fe3+ ions. The student is asked to find the total mass of iron ions and t...

A student is asked to find the enthalpy change for the reaction between anhydrous magnesium sulfate and water. MgSO4(s) + 7H2O(l) → MgSO4•7H2O(s) T...

A student is asked to determine the acid dissociation constant, Kₐ, for butanoic acid, CH3CH2CH2COOH. Kₐ = [CH3CH2CH2COO⁻][H⁺] / [CH3CH2CH2COOH] Th...

Equations involving four enthalpy changes are shown. Na(g) → Na⁺(g) + e⁻ ΔH = W Na(g) → Na²⁺(g) + 2e⁻ ΔH = X Na(s) → Na(g) ΔH = Y Na(s) → Na²⁺(g) +...

This question refers to isolated gaseous atoms in the ground state. In which atom are all electrons paired?

Which sample contains the most iodine?

When a small sample of hydrocarbon Q is completely combusted, it produces 3.52 g of carbon dioxide and 1.44 g of water. What could be the structure...

Ethane and ethene are both hydrocarbon molecules. What is a feature of both molecules?

Elements J and L are both in Group 15. J and L each form a gaseous covalent hydride in which their oxidation number is –3. In the liquefied forms o...

Which gas will behave least like an ideal gas at 150 °C and 101 kPa?

When an evacuated glass bulb of volume 200 cm³ is filled with a gas at 300 K and 101 kPa, the mass of the bulb increases by 0.68 g. The gas obeys t...

The standard enthalpy of formation of NO₂(g) is +33.2 kJ mol⁻¹. The standard enthalpy of formation of N₂O₄(g) is +9.2 kJ mol⁻¹. What is the standar...

Separate samples of 25.0 cm³ of 0.1 mol dm⁻³ NaOH(aq) are added to each of three different acid solutions, as described. The temperature of each of...

NCl₃ reacts with H₂O. NCl₃ + 3H₂O → NH₃ + 3HClO The oxidation state of nitrogen does not change in this reaction. Which statement is correct?

In which row do the oxidation numbers of vanadium increase?

A synthesis for methanol is shown. CO₂(g) + 3H₂(g) ⇌ CH₃OH(g) + H₂O(g) ΔH = −49 kJ mol⁻¹ Which conditions would produce the greatest yield of metha...

Hydrogen and iodine can react reversibly to produce hydrogen iodide. The equation is shown. H₂(g) + I₂(g) ⇌ 2HI(g) 4.00 mol of hydrogen gas and X m...

A large amount of N₂O(g) decomposes into nitrogen gas and oxygen gas in the presence of a tiny amount of a gold foil catalyst. The gold foil provid...

The Haber process for the manufacture of ammonia is represented by the equation shown. N₂(g) + 3H₂(g) ⇌ 2NH₃(g) ΔH = −92 kJ mol⁻¹ Which statement i...

NH₃(aq) is added to separate samples of NaCl(aq), MgCl₂(aq), BaCl₂(aq) and SiCl₄(l). Under the conditions of this experiment, only two samples will...

Why is the ionic radius of a sulfide ion larger than the ionic radius of a potassium ion?

The table gives information about calcium carbonate and calcium hydroxide. Which row is correct?

Q is a Group 2 metal. An excess of QCO₃(s) is added to H₂SO₄(aq) followed by filtration. A sample of QSO₄ is then obtained by evaporation of the fi...

X, Y and Z are three elements in Group 17. X₂ has weaker covalent bonds than Y₂. X₂ has stronger instantaneous dipole-induced dipole forces between...

Chlorine reacts with aqueous sodium hydroxide forming two chlorine-containing products. Which row shows the oxidation states of chlorine in the pro...

A catalytic converter reduces the amount of pollutants in the fumes from a car exhaust. Which row identifies a pollutant and shows how it is remove...

Solid R is added to a solution of ammonium nitrate and the mixture is heated. A gas is given off which turns red litmus to blue. What could be R?

A skeletal formula is shown. [Figure showing a skeletal formula of 3,7-dimethylocta-2,4,6-triene] What is the total number of stereoisomers includi...

The molecular formula CH₃ can represent an anion, a cation or a free radical. Species with the molecular formula CH₃ can act as an electrophile, a ...

Compound Z, C₇H₁₃Br, has two chiral centres. A sample of Z contains all four possible optical isomers. This sample of Z reacts with hot ethanolic N...

The free-radical substitution reaction between methane and chlorine involves initiation, propagation and termination stages. Which row is correct?

The alkene shown reacts with an excess of HBr via an electrophilic addition reaction. [Figure showing skeletal formula of 2,5-dimethylhex-2-ene] Wh...

The diagram shows the structures of two halogenoalkanes, P and Q. [Figure showing skeletal formulas of 2-bromo-2-ethylpentane (P) and 2-fluoro-2-et...

The structure of coniine is shown. [Figure showing the skeletal formula of coniine] Coniine can be synthesised by reacting ammonia with a dibromo c...

Primary alcohols can be oxidised to aldehydes using either acidified potassium dichromate(VI) or acidified potassium manganate(VII). The reaction m...

Which reaction has a product that gives a yellow precipitate when treated with alkaline I₂(aq)?

The skeletal formula of M is shown. [Figure showing skeletal formula of M, which is CH₃–CH(OH)–C(=O)–CH(OH)–CHO] M is reacted with an excess of LiA...

Which compound forms a precipitate when mixed with 2,4-DNPH reagent and also forms a precipitate when mixed with Fehling's reagent?

Which reaction is a redox reaction?

Ethyl butanoate is a flavouring, with a fruity flavour. Which row is correct?

Cyclohexene, as shown in the diagram, can form an addition polymer. [Figure showing cyclohexene] Which structure represents a section of the polymer?

Three organic compounds are listed. 1 ethanal 2 propan-1-ol 3 propan-2-ol Which compounds will have a mass spectrum that contains a fragment peak a...

Calcium, magnesium and radium are Group 2 elements. Radium follows the same trends as the other members of Group 2.