Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
A reaction between carbon and oxygen is shown. C(s) + ½O2(g) → CO(g) How can the standard enthalpy change of this reaction be described correctly? ...
Hydrochloric acid reacts with zinc. 2HCl(aq) + Zn(s) → ZnCl2(aq) + H2(g) What will increase the rate of this reaction but will not change the Boltz...
The element astatine, At, is below iodine in Group 17 of the Periodic Table. Which statements concerning At are likely to be correct? 1 It is a dar...
Which statements are correct? 1 Aluminium chloride dissolves in water to give an acidic solution. 2 Magnesium chloride dissolves in water to give a...
Ethanal and hydrogen cyanide react together. The reaction mechanism involves cyanide ions. [Figure 37.1] Which statements about this mechanism are ...
Which compounds will produce a yellow precipitate with alkaline aqueous iodine? [Figure 38.1]
Which statements apply to tetrafluoromethane? 1 It is rapidly decomposed by ultraviolet radiation. 2 It is less harmful to the ozone layer than dic...
Which statements comparing ethene and ethane are correct? 1 The bond angles in ethene are larger than the bond angles in ethane. 2 Ethene reacts mu...
Group 2 metals form alkaline solutions in water.
The Group 17 elements, chlorine, bromine and iodine, are non-metals that show trends in their physical and chemical properties.
Glycerol, CH2(OH)CH(OH)CH2OH, is widely used in the food industry and in pharmaceuticals.
In this experiment you will determine the enthalpy change, AH, for the catalytic decomposition of hydrogen peroxide into water and oxygen. H2O2(aq)...
Iron is a transition element in the fourth period. Iron forms compounds containing the ions Fe²⁺ and Fe³⁺.
Group 2 metals form stable carbonates and sulfates.
Gold is an unreactive metal that can only be oxidised under specific conditions. Some relevant half-equations and their standard electrode potentia...
Compound F has been found in small quantities in some cereals and dried fruit. [Figure 4.1]
Gallic acid, C₇H₆O₅, is a naturally occurring aromatic molecule. [Figure 5.1]
Valinol can be synthesised by the following reactions. Reaction 1 uses valine as the starting material. [Figure 6.1]
Brass is an alloy of copper and zinc. Typical copper concentrations vary from 50% to 85%, depending upon the properties needed in the alloy. There ...
The activation energy, Eₐ, of the reaction between aqueous manganate(VII) ions, MnO₄⁻(aq), and aqueous ethanedioate ions, C₂O₄²⁻(aq), can be determ...
The table shows the numbers of protons, neutrons and electrons in four different particles, W, X, Y, and Z. number of protons number of neutrons nu...
Where in the Periodic Table is the element that has an outer electron shell arrangement of 4s²4p³? Group Period A 13 3 B 13 4 C 15 3 D 15 4
Substance Q is a hydrocarbon. When 1.00 g of Q is completely burned, 3.22 g of carbon dioxide is produced. What could be the identity of Q?
Originally, chemists thought indium oxide had the formula InO. By experiment they showed that 4.8 g of indium combined with 1.0g of oxygen to produ...
In which substance are the only intermolecular forces temporary dipole-induced dipole attractions?
A solution contains 0.25 g of sulfur dioxide in 1.00 dm³ of water. Which volume of sulfur dioxide, measured at 50 °C and a pressure of 1 × 10⁵ Pa, ...
An experiment was performed to determine the enthalpy of combustion of ethanol. [Figure showing experimental setup for calorimetry] The data collec...
VO₂Cl reacts with NaI under acidic conditions. 2VO₂Cl + 2H₂SO₄ + 2NaI → VOCl₂ + VOSO₄ + I₂ + Na₂SO₄ + 2H₂O The oxidation state of Cl is −1 in VO₂Cl...
In which reaction is water behaving as a Brønsted-Lowry base?
A large excess of marble chips is reacted with 25 cm³ of 1.0 mol dm⁻³ hydrochloric acid at 40 °C. How is the result different when the reaction is ...
The Boltzmann distribution curve for a gaseous mixture of ethene and hydrogen is shown. Nickel is an effective catalyst for the reaction that occur...
Which observations are made when a sample of silicon chloride, SiCl₄, is added to a beaker of water?
Which row is correct? statement reason A The first ionisation energy of phosphorus is greater than that of magnesium. electron is lost from a 3p or...
Which row correctly describes one property of barium and one property of barium oxide? observation when barium metal is added to water pH of soluti...
An anhydrous white salt, Z, is heated strongly for 30 minutes. A mixture of gases is given off. The solid remaining in the test-tube is then dissol...
Chlorine gas is reacted with aqueous sodium hydroxide. The oxidation number of chlorine changes from 0 to –1 and also from 0 to +1. Under which con...
When concentrated sulfuric acid reacts with sodium iodide the products include sulfur, iodine, hydrogen sulfide and sulfur dioxide. Which statement...
NO, NO₂, CO and unburnt hydrocarbons are present in the exhaust gases of internal combustion engines. When catalytic converters are used to remove ...
Methylamine, CH₃NH₂, has similar chemical properties to ammonia, NH₃. Methylamine reacts with hydrogen chloride to form a white crystalline salt, m...
The structures of citric acid and isocitric acid are shown. [Figure showing structures of citric acid and isocitric acid] How many chiral centres d...
How many tertiary alcohols have the molecular formula C₆H₁₄O?
The diagram shows the structure of a bromo compound that may be formed by the reaction of bromine with a hydrocarbon. [Figure showing structure of ...
Part of the structure of strobilurin is shown. R and R' are inert groups. [Figure showing partial structure of strobilurin] Strobilurin is warmed w...
Which compound produces a ketone when refluxed with an acidified solution of potassium dichromate(VI)?
Dibromopentanes can undergo 'double elimination' reactions to produce hydrocarbons. 2NaOH + C₅H₁₀Br₂ → C₅H₈ + 2NaBr + 2H₂O Which isomer produces on...
The diagram shows the formation of compound Y from compound X in a chemical reaction. R₁ and R₂ are alkyl groups. [Figure showing X + HCN (KCN cata...
In this question you can assume that ¹H and ³H have the same chemical properties. A sample of ethanal contains only one isotope of hydrogen, ¹H. It...
Which reaction gives butanoic acid as one of its products?
When reactant X is treated with a suitable reagent, products Y and Z are formed. Infrared spectra of X, Y and Z are shown. [Figure showing IR spect...
A sample of 17.15 mol HI(g) is in dynamic equilibrium with 2.27 mol H₂(g) and 2.84 mol I₂(g) in a volume of 1 m³ at 764 K and 141 kPa. H₂(g) + I₂(g...