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.
Which series shows molecules in order of increasing bond angle?
What is the volume of steam produced when 1.00g of ice is heated to 323°C at a pressure of 101 kPa?
Solid carbon dioxide, CO₂, is similar to solid iodine, I₂, in its structure and properties. Carbon is in Group 14. Silica, SiO₂, is a Group 14 comp...
An article in a science magazine contains the following statement. 'It is lighter than a feather, stronger than steel, yet incredibly flexible and ...
Which equation has an enthalpy change of reaction which corresponds to the standard enthalpy change of atomisation of chlorine?
In an experiment, 2.00 mol of hydrogen and 3.00 mol of iodine were heated together in a sealed container and allowed to reach equilibrium at a fixe...
Consecutive elements X, Y and Z are in Period 3 of the Periodic Table. Element Y has the highest first ionisation energy and the lowest melting poi...
When dealing with a spillage of metallic sodium it is important that no toxic or flammable products are formed. Which material should be used if th...
Chlorine gas is widely used to treat contaminated water. Which species present in water when chlorine gas has been added is responsible for killing...
Which row of the table is correct?
Hydrogen chloride gas and hydrogen iodide gas have different thermal stabilities. The difference is due to a difference in the energies of some of ...
Ammonium sulfate, (NH₄)₂SO₄, and ammonium nitrate, NH₄NO₃, are used as fertilisers. These salts have different percentages by mass of nitrogen. The...
River water in a chalky agricultural area contains Ca²⁺, Mg²⁺, CO₃²⁻, HCO₃⁻, Cl⁻ and NO₃⁻ ions. In a water treatment plant, such water is treated b...
After black and white photographic film has been developed, unreacted silver bromide is removed by reaction with sodium thiosulfate. AgBr + 2Na₂S₂O...
People who take statin drugs to control their blood cholesterol may also take 'coenzyme Q₁₀'. [Figure showing a simplified structure of one form of...
Geraniol and nerol are compounds found in some flower fragrances. They are isomers of each other. [Figure showing structures of geraniol and nerol]...
A section showing two repeat units of an addition polymer is shown. [Figure showing a section of an addition polymer] What is the identity of the m...
But-2-ene-1,4-diol is converted in two steps through an intermediate X into oxobutanedioic acid. HOCH₂CH=CHCH₂OH but-2-ene-1,4-diol step 1 X step 2...
Hydrogen bromide can be added to T to give compound U. Compound U can be hydrolysed to compound V. [Figure showing structures of T, U, V and reacti...
Structural isomerism and stereoisomerism should be considered in answering this question. Compound J is reacted with KOH dissolved in ethanol. Thre...
Which row correctly shows a primary, a secondary and a tertiary alcohol?
The fragrance compounds of perfumes are often dissolved in solvent Y, which has a molecular formula C₇H₁₂O₄. It is made by reacting propane-1,2-dio...
Which mixture could be used to produce propyl methanoate?
Which statement about poly(chloroethene) is correct?
Which molecules have an overall dipole moment? 1 carbon monoxide, CO 2 phosphine, PH₃ 3 carbon dioxide, CO₂
The diagram illustrates the enthalpy changes of a set of reactions [Figure showing enthalpy cycle R -> S, T -> S, T -> U, U -> R] Which statements ...
Which statements about reversible reactions are correct? 1 An increase in concentration of a reactant always increases the concentration of the pro...
A chemist puts a sample of dilute aqueous hydrochloric acid into beaker 1. She adds a sample of zinc and measures the rate of production of hydroge...
In some rice-growing parts of the world, farmers use a combination of paddy fields and a fish farm. Rice paddy fields are flooded for much of the g...
A sample containing 0.40 mol of calcium nitrate was decomposed by heating in a roaring Bunsen burner flame until there was no further decomposition...
Which reagents, when used in an excess, can be used to make sodium lactate, CH₃CH(OH)CO₂Na, from lactic acid, CH₃CH(OH)CO₂H? 1 Na 2 NaHCO₃ 3 NaOH
Chlorine atoms in the upper atmosphere cause the breakdown of ozone. Cl + O₃ → O₂ + ClO ClO + O → Cl + O₂ Which statements are correct when referri...
An unknown organic compound Z reacts with sodium to give a combustible gas as one product. Z does not give a yellow precipitate with alkaline aqueo...
Compound X has the molecular formula C₃H₆O₃. Heating X under reflux with acidified K₂Cr₂O₇ forms HO₂CCOCO₂H. Reacting X with NaBH₄ forms HOCH₂CH(OH...
Which ion has the same electronic configuration as Cl¯?
Compounds J and K each contain 40% carbon by mass. What could J and K be?
Two moles of compound P were placed in a sealed container. The container was heated and P was partially decomposed to produce Q and R only. A dynam...
The boiling points of methane, ethane, propane and butane are given. compound CH4 boiling point/K 112 compound CH3CH3 boiling point/K 185 compound ...
The characteristic smell of garlic is due to alliin. [Figure showing the structure of alliin with bond angles x, y and z marked]. What are the appr...
Which gas sample contains the fewest molecules?
A student mixed 25.0 cm³ of 4.00 mol dm⁻³ hydrochloric acid with an equal volume of 4.00 mol dm⁻³ sodium hydroxide. The initial temperature of both...
HOCl(aq) is the molecule that kills bacteria when chlorine is added to water. The following reaction produces this molecule. Cl₂(g) + H₂O(l) ⇌ HOCl...
All the reactants and products of an exothermic reaction are gaseous. Which statement about this reaction is correct?
Oxidation of ethanedioate ions by acidified manganate(VII) ions is very slow at room temperature. 2MnO₄⁻ + 5C₂O₄²⁻ + 16H⁺ → 2Mn²⁺ + 10CO₂ + 8H₂O Mn...
Ammonia is manufactured from nitrogen and hydrogen using the Haber process. N₂(g) + 3H₂(g) ⇌ 2NH₃(g) What is the expression for K for this equilibr...
The electrical conductivities of two compounds, Y and Z, are shown in the table. conductivity of the compound in the liquid state conductivity of t...
Which reagent, when mixed with ammonium sulfate and then heated, liberates ammonia?
Why does barium react more rapidly with cold water than magnesium does?
The magnitude of property X of five elements from the third period of the Periodic Table, P, Q, R, S and T is shown. P, Q, R, S and T have consecut...
Some uses of chlorine and bromine are given. Which is a use of bromine?