IGCSE Chemistry (0620) — October–November 2024, Paper 23
40 questions · every question answerable online with instant point-by-point AI marking against the official mark scheme.
Start with Question 1 →A sample of ethanol is left in an open beaker at room temperature. After 24 hours, no ethanol remains in the beaker. What has happened to the ethanol? A It has boiled. B It has…
Answer this question and get it marked →A gas is in a sealed container with a fixed volume. Which statements describe what happens to the molecules in the gas when the temperature is increased? 1 They move more slowly.…
Answer this question and get it marked →What happens when sodium atoms combine with chlorine atoms to form sodium chloride? A Sodium atoms each gain one electron, and chlorine atoms each lose one electron. B Sodium…
Answer this question and get it marked →The table shows some properties of four substances. substance melting point electrical conductivity when solid electrical conductivity when molten --- --- --- --- 1 high poor poor…
Answer this question and get it marked →Which statement about methane is correct? A In methane, positive hydrogen ions are attracted to negative carbon ions. B In methane, electrons are shared between carbon atoms and…
Answer this question and get it marked →A sample of iridium has a relative atomic mass of 192.29. The sample contains two isotopes only. 64.50% of the sample is 193-Ir. What is the other isotope in the sample? A 189-Ir…
Answer this question and get it marked →Ammonium iron(III) citrate contains in its formula: more than one ammonium ion; one iron ion; two C6H4O7 4- ions. What is the formula of ammonium iron(III) citrate? A…
Answer this question and get it marked →Silicon(IV) oxide reacts with chlorine and carbon to form liquid silicon(IV) chloride, SiCl4, and carbon dioxide gas. If the reaction is carried out at r.t.p., which symbol…
Answer this question and get it marked →The structure of ethene is shown (CH2=CH2). How many hydrogen atoms and how many carbon atoms are in one mole of ethene? hydrogen atoms carbon atoms --- --- --- A 2.4 x 10^24 1.2…
Answer this question and get it marked →A known volume and concentration of aqueous sodium hydroxide is titrated against dilute hydrochloric acid. The volume of dilute hydrochloric acid needed to exactly neutralise the…
Answer this question and get it marked →Two different substances are electrolysed using inert electrodes in two separate experiments. Hydrogen is produced in both experiments. Which row identifies the two substances and…
Answer this question and get it marked →Aqueous copper(II) sulfate can be electrolysed using either carbon electrodes or copper electrodes. Which statement describes what happens at the positive electrode? A Copper is…
Answer this question and get it marked →Which statement about a hydrogen-oxygen fuel cell is not correct? A Chemical energy is converted into electrical energy. B Hydrogen is oxidised. C The reaction that takes place is…
Answer this question and get it marked →Which reaction pathway diagram is correctly labelled? (Four energy-vs-progress diagrams A-D are shown, each labelling the activation energy Ea and the enthalpy change ΔH; the…
Answer this question and get it marked →Which row describes a reaction where the overall energy change is exothermic? energy needed for breaking bonds / kJ energy released by forming bonds / kJ temperature of the…
Answer this question and get it marked →Which process involves a physical change only? A heating calcium carbonate strongly B burning wood C melting an ice cube D mixing an acid and a base
Answer this question and get it marked →In the Haber process, an equilibrium is established. N2(g) + 3H2(g) ⇌ 2NH3(g) The forward reaction is exothermic. Which change to the reaction conditions will move the position of…
Answer this question and get it marked →The flow chart shows some properties of a metal oxide: it reacts with HCl(aq) to give a salt + water (so it is basic) and reacts with NaOH(aq) to give a salt + water (so it is…
Answer this question and get it marked →Which statement about reactants in redox reactions is correct? A An oxidising agent donates electrons, and a reducing agent accepts electrons. B When one element gains electrons,…
Answer this question and get it marked →Aluminium is extracted from aluminium oxide by electrolysis. The ionic half-equation for the reaction at one of the electrodes is shown. Al3+ + 3e- - Al Which row describes the…
Answer this question and get it marked →Which statement about dilute hydrochloric acid is correct? A It is a strong acid as it fully dissociates. B It is a strong acid as it partially dissociates. C It is a weak acid as…
Answer this question and get it marked →Which row describes and gives the formula of hydrated copper(II) sulfate? description of hydrated copper(II) sulfate formula of hydrated copper(II) sulfate --- --- --- A aqueous…
Answer this question and get it marked →The equations for three reactions are shown. 1 Pb(NO3)2(aq) + 2KI(aq) - PbI2(s) + 2KNO3(aq) 2 2AgNO3(aq) + CuI2(aq) - Cu(NO3)2(aq) + 2AgI(s) 3 CuO(s) + H2SO4(aq) - CuSO4(aq) +…
Answer this question and get it marked →Acidified potassium dichromate(VI), K2Cr2O7, is used to oxidise ethanol, C2H5OH. The ionic equation for the reaction is shown. 3C2H5OH + 2Cr2O7 2- + 16H+ - 3CH3COOH + 4Cr3+ +…
Answer this question and get it marked →Which statements describe the Periodic Table? 1 The elements are arranged in order of their nucleon number. 2 The elements are arranged in order of their proton number. 3 It is…
Answer this question and get it marked →Which row shows the correct order of reactivity of the four named metals? most reactive least reactive --- --- --- --- --- A magnesium copper zinc silver B magnesium zinc copper…
Answer this question and get it marked →Four iron nails are added to four different metal sulfate solutions. In which solution does a displacement reaction occur? A copper(II) sulfate B magnesium sulfate C sodium…
Answer this question and get it marked →A fertiliser contains ammonium nitrate and potassium phosphate. Why is the fertiliser described as an NPK fertiliser? A It provides nitrogen, which is an essential element for…
Answer this question and get it marked →What are the approximate percentages of oxygen and nitrogen in clean, dry air? percentage of oxygen percentage of nitrogen --- --- --- A 19 80 B 21 78 C 80 19 D 78 21
Answer this question and get it marked →Which compounds have similar chemical properties? A butanol and butanoic acid B ethane and ethene C methane and butane D propene and propanol
Answer this question and get it marked →Four statements about organic compounds P, Q, R and S are listed. P is a saturated hydrocarbon. The formula of Q is CH3CH3. A molecule of R contains only one oxygen atom. Compound…
Answer this question and get it marked →The structure of an organic compound is shown: CH3CH2Cl (a two-carbon chain with one chlorine atom). What is the name of the compound? A chloroethane B chloroethene C…
Answer this question and get it marked →Which statement about the manufacture of ethene from larger alkane molecules is correct? A A low temperature is required. B The process is called cracking. C The process requires…
Answer this question and get it marked →Which processes are used to make ethanoic acid? 1 heating ethanol with acidified aqueous potassium manganate(VII) 2 bacterial oxidation of ethanol 3 distilling ethanol using a…
Answer this question and get it marked →Which statement about propene, C3H6, is correct? A Propene reacts with bromine in the dark in a substitution reaction. B Propene reacts with steam in the presence of an alkaline…
Answer this question and get it marked →How many of each type of bond are present in ethanoic acid, CH3COOH? C-H C-C C=O --- --- --- --- A 3 1 1 B 3 0 2 C 4 0 2 D 4 1 2
Answer this question and get it marked →Which diagram represents the structure of a protein? (Four structures A-D are shown; the correct one shows amino-acid units joined by amide/peptide -N-C(=O)- linkages.) A B C D
Answer this question and get it marked →The chromatogram of substance S is shown, with distances W, X, Y and Z labelled: Z is the distance from the baseline to the solvent front, and the spot of substance S is between…
Answer this question and get it marked →Some information about solid silver chloride and solid sodium chloride is shown. - Silver chloride and sodium chloride do not dissolve in kerosene. - Silver chloride is insoluble…
Answer this question and get it marked →Which statement describes how a flame test is done? A The tip of a clean wire is dipped into the substance and the wire is placed in a blue Bunsen burner flame. B The tip of a…
Answer this question and get it marked →← October–November 2024 Paper 31 · October–November 2024 Paper 22 →