Cambridge & Pearson Edexcel Past Paper Questions
Browse 35,704 questions from Cambridge O-Level & A-Level and Pearson Edexcel IGCSE & IAL exams. Click any question to practice.
An aqueous solution of cobalt(II) contains the [Co(H2O)6]2+ complex ion.
Benzene reacts with bromine in the presence of an aluminium bromide catalyst, AlBr3, to form bromobenzene. This is a substitution reaction. No addi...
Silver carbonate, Ag2CO3, is sparingly soluble in water. The numerical value of the solubility product, Ksp, for silver carbonate is 6.3 × 10–12 at...
Manganese(IV) oxide, MnO2, catalyses the decomposition of hydrogen peroxide, H2O2, as shown. MnO2 2H2O2(aq) → 2H2O(l) + O2(g) The mechanism involve...
The electronic configuration of transition element Q is [Ar] 3d² 4s².
Trichloromethane and propanone are both organic liquids. The molecules within each liquid are attracted to each other by relatively weak permanent ...
Nitrogen dioxide can be prepared by strongly heating anhydrous lead nitrate, Pb(NO₃)₂(s). The thermal decomposition occurs according to the equatio...
A student plans to carry out an experiment to find the relative molecular mass, Mr, of a soluble acidic gas, X, by finding the mass of a measured v...
Each student in a class of nine students performs an experiment to find the formula of a chloride of iron. Each student prepares the chloride of ir...
Which statement about the Avogadro constant is correct?
Which equation represents the first ionisation energy of iodine?
The structures represent three compounds, each with four carbon atoms per molecule. [Diagram X: CH₃CH₂CH₂COOH] [Diagram Y: CH₃COOCH₂CH₃] [Diagram Z...
The structural formula of alliin is shown. [Diagram of alliin with bond angles x, y, z marked] What are the approximate bond angles x, y and z in a...
Flask Q contains 5 dm³ of helium at 12 kPa pressure. Flask R contains 10 dm³ of neon at 6 kPa pressure. If the flasks are connected at constant tem...
Sodium chloride, water and air represent three states of matter – solid, liquid and gas. Which row is correct?
The reaction pathway diagram for the catalysed reaction and the uncatalysed reaction between N₂ and H₂ is shown. N₂(g) + 3H₂(g) ⇌ 2NH₃(g) [Reaction...
Nitrogen and oxygen can react together to form nitrogen monoxide, NO. N₂ + O₂ ⇌ 2NO ΔH = +180 kJ mol⁻¹ What is the bond energy of the bond between ...
The equation for a redox reaction is shown. SnCl₂(aq) + 2HgCl₂(aq) → SnCl₄(aq) + Hg₂Cl₂(s) Which species is being oxidised in this reaction?
3.60 moles of hydrogen gas and 2.00 moles of iodine vapour are placed in a reaction vessel which is then sealed and maintained at a constant temper...
Two chemicals, X and Y, react together in solution to give product Z. The rate of formation of product Z at the start of the reaction was measured ...
A sample of SiCl₄ is added to cold water. Which statement describes the mixture formed at the end of the reaction?
L and M are elements in Period 3 of the Periodic Table. • The oxide of L is a solid at room temperature. This oxide has a giant structure. • The ch...
A farmer requires a solid compound to raise the pH of the soil in a field from 5.5 to above 6.0. Which compound could the farmer use?
Which row gives mixtures that both result in the oxidation of a halide ion?
Chlorine gas is widely used to treat contaminated water. When chlorine is added to water, which chemical species present is responsible for killing...
What is an environmental consequence of the uncontrolled use of nitrate fertilisers?
Compound P is treated with an excess of hydrogen gas in the presence of a nickel catalyst. The product Q is fully saturated. [Diagram of compound P...
Hexadeca-10,12-dien-1-ol is produced by silk moths from hexadecanoic acid in a three-step enzymic process. [Reaction scheme from hexadecanoic acid ...
Compound X can be converted into compound Y in a single step. [Reaction scheme X to Y with structures] What could be the identity of X?
Methane and bromine react by free radical substitution. P and Q are involved in the reaction mechanism. • are both involved in propagation steps as...
A few drops of 2-bromopropane were placed in a test-tube. An equal volume of aqueous silver nitrate was added. A precipitate was formed. The experi...
Sodium methoxide, Na⁺CH₃O⁻, reacts with 2-chloro-2-methylpropane in a nucleophilic substitution reaction. The nucleophile is the CH₃O⁻ ion. Which r...
Alcohol X reacts with concentrated sulfuric acid to produce a mixture of products. Two of the products are structural isomers of each other. What c...
Which reaction will form a strong organic base?
Which reaction mechanism for the formation of C₂H₅CH(OH)(CN) is correct?
The synthesis shown may be used for the production of propan-1-ol. [Reaction scheme] Which row gives the correct reagents for steps 1 and 2?
The molecular formula of Z is C₄H₈O. The infra-red spectrum of Z is shown. [Infrared spectrum graph] What could be Z?
In which ions are the number of electrons equal to the number of neutrons? 1 ¹⁹F⁻ 2 ³¹P³⁻ 3 ²³Na⁺
Compound X is a straight chain hydrocarbon with an Mr of 84. What can be determined about X? 1 empirical formula 2 molecular formula 3 whether X co...
When a sample of ammonium chloride is warmed it decomposes into ammonia and hydrogen chloride gas. NH₄Cl(s) → NH₃(g) + HCl(g) reaction 1 [Diagram o...
Hydrogen chloride gas is formed by the reaction shown. H₂(g) + Cl₂(g) → 2HCl(g) What will change the average kinetic energy of the reacting gas par...
Which oxides will cause a change in pH when added to water? 1 CaO 2 Al₂O₃ 3 SiO₂
Which reaction routes can be used to make a pure sample of barium sulfate? [Three reaction schemes]
Cortisone is a synthetic hormone. [Diagram of cortisone structure] Which classes of alcohol does this molecule contain? 1 primary alcohol 2 seconda...
Which changes are commonly involved in the formation of an addition polymer? 1 the formation of a σ-bond 2 the breaking of a π-bond 3 the change in...
Which alcohols can be oxidised to form an organic compound which will give coloured precipitates with both 2,4-dinitrophenylhydrazine reagent and a...
Which mixtures form a carboxylic acid as one of the products? [Three reaction schemes]
Ethanedioic acid, HO₂CCO₂H, has a relative molecular mass of 90.0.
Carbon monoxide gas, CO(g), and nitrogen gas, N₂(g), are both diatomic molecules. (a) The diagram shows the arrangement of outer electrons in a mol...
Sodium halide salts react with concentrated sulfuric acid at room temperature.