IGCSE Chemistry (0620) — May–June 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 →Sodium chloride is a liquid at 900 °C. Which row describes the arrangement and the motion of the particles in sodium chloride at 900 °C? (columns: arrangement of particles; motion…
Answer this question and get it marked →Hydrogen chloride gas, HCl, reacts with ammonia gas, NH3, to form solid ammonium chloride. In a tube with a source of hydrogen chloride gas at one end and a source of ammonia gas…
Answer this question and get it marked →Substances P and Q both conduct electricity. P is a mixture of two different types of atom. Q is made of only one type of atom. Which row describes P and Q? (columns: P; Q) A…
Answer this question and get it marked →An atom of element R contains 15 protons, 16 neutrons and 15 electrons. What is R? A gallium B phosphorus C sulfur D zinc
Answer this question and get it marked →Which molecule contains a double covalent bond between two atoms of the same element? A carbon dioxide B ethanol C ethene D nitrogen
Answer this question and get it marked →Silicon(IV) oxide is a covalently bonded compound. Which statements are correct? 1 Silicon atoms form four single bonds in silicon(IV) oxide. 2 Oxygen atoms form two double bonds…
Answer this question and get it marked →The equation for the reaction of iron(III) oxide with carbon monoxide is shown: Fe2O3 + 3CO → 2Fe + 3CO2 What is the percentage yield of iron when 16.8 g of carbon monoxide reacts…
Answer this question and get it marked →What is the volume of 14.5 g of gaseous butane, C4H10, at room temperature and pressure? [Mr C4H10 = 58; molar gas volume = 24 dm³/mol at r.t.p.] A 96.0 cm³ B 6.0 cm³ C 96.0 dm³ D…
Answer this question and get it marked →Aqueous copper(II) sulfate is electrolysed using copper electrodes connected to a d.c. power supply. Which statement describes what happens during the electrolysis? A Copper atoms…
Answer this question and get it marked →Electrolysis is carried out on concentrated aqueous potassium bromide using inert electrodes. Which products are formed at the anode and the cathode? (columns: anode; cathode) A…
Answer this question and get it marked →Hydrogen-oxygen fuel cells and gasoline are each used to power cars. Which statement describes an advantage of using hydrogen-oxygen fuel cells in cars in comparison with gasoline…
Answer this question and get it marked →Plant cells use energy from sunlight for photosynthesis. Which row describes and explains the energy change that occurs? (columns: type of energy change; explanation of energy…
Answer this question and get it marked →Two different experiments are done to find the enthalpy change, ΔH, of each reaction. The temperature is measured at the beginning and after 3 minutes. In experiment 1 the…
Answer this question and get it marked →The reaction pathway diagram for an endothermic reaction is shown; u, v and w are known energy values, with reactants at energy u and products at the higher energy v, and the peak…
Answer this question and get it marked →Which process is a physical change? A burning a piece of magnesium B reacting calcium carbonate with hydrochloric acid C melting an ice cube D the rusting of an iron nail
Answer this question and get it marked →The Contact process is used to convert sulfur dioxide to sulfur trioxide. Vanadium(V) oxide is the catalyst: 2SO2(g) + O2(g) ⇌ 2SO3(g) The forward reaction is exothermic. Which…
Answer this question and get it marked →The equation for the decomposition of hydrogen peroxide, H2O2, is shown: 2H2O2 → 2H2O + O2 In an experiment, the total volume of oxygen produced is 100 cm³. The experiment is…
Answer this question and get it marked →Nitrogen reacts with hydrogen to form ammonia in the presence of an iron catalyst. The reaction is reversible: N2(g) + 3H2(g) ⇌ 2NH3(g) Which statement about this reaction is…
Answer this question and get it marked →The equation for a redox reaction is shown: H2O2 + 2KI + H2SO4 → I2 + K2SO4 + 2H2O "Potassium iodide is ...(1)... agent in this reaction because iodide ions ...(2)... electrons."…
Answer this question and get it marked →Element E is in Group II of the Periodic Table. Which row describes element E and its oxide? (columns: element E; oxide of E) A metal; acidic B metal; basic C non-metal; acidic D…
Answer this question and get it marked →Lead(II) iodide is formed as a precipitate in the reaction shown: Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2NaNO3(aq) Which method is used to separate the lead(II) iodide from the…
Answer this question and get it marked →Which statement explains why sulfur, S, has similar chemical properties to selenium, Se? A They both have the same number of electrons in their outer electron shell. B They are…
Answer this question and get it marked →Atoms of sodium, rubidium and element Q each have one outer shell electron. Some properties of these elements are shown (element; melting point in °C; boiling point in °C; density…
Answer this question and get it marked →Which statement about elements in Group VIII of the Periodic Table is correct? A They all have a full outer shell of electrons. B They all react with Group I elements to form…
Answer this question and get it marked →The electrical conductivity of magnesium is tested. Magnesium is then added to dilute sulfuric acid. A gas, W, is produced. Which row describes the electrical conductivity of…
Answer this question and get it marked →Aluminium metal is extracted from its purified ore by electrolysis. Which statement about the electrolyte in this process is correct? A The electrolyte is purified molten bauxite…
Answer this question and get it marked →Part of the reactivity series is shown (most to least reactive): potassium, X, calcium, Y, aluminium. Which metals are represented by X and Y? (columns: X; Y) A copper; magnesium…
Answer this question and get it marked →Some substances found in water extracted from a river are listed: 1 plastics 2 nitrates 3 oxygen Which substances are harmful to aquatic life? A 1 and 2 B 1 and 3 C 2 only D 3 only
Answer this question and get it marked →Car engines which use gasoline as a fuel produce oxides of nitrogen. Oxides of nitrogen are removed from the exhaust gases. Which statements about the formation or removal of…
Answer this question and get it marked →Which structures represent a pair of structural isomers? 1 CH3CH2CH2CH2CH2CH3 2 CH3CH2CH2CH2CH(CH3)2 3 CH3CH(CH3)CH2CH2CH3 4 CH3CH(CH3)CH2CH2CH2CH3 A 1 and 2 B 1 and 3 C 2 and 4 D…
Answer this question and get it marked →Alkanes are a homologous series of hydrocarbons. The table shows the names and boiling points of the first four members (name; boiling point / °C): methane -162; ethane -89;…
Answer this question and get it marked →Which displayed formula (A, B, C or D) represents the ester formed by the reaction of propan-1-ol with ethanoic acid? The correct ester is propyl ethanoate, CH3COOCH2CH2CH3, shown…
Answer this question and get it marked →Ethanol can be manufactured by fermentation and by the catalytic addition of steam to ethene. Which statement identifies an advantage of using one of these methods? A Catalytic…
Answer this question and get it marked →Which statement about carboxylic acids is correct? A They react with alkalis to form a salt and water. B They react with metals to form a salt and water. C They react with metal…
Answer this question and get it marked →The structure of a polymer is shown (a polyamide, with repeating -N(H)-C(=O)- amide linkages). Which statement about this polymer is correct? A Alkenes are polymerised to make the…
Answer this question and get it marked →Methane undergoes substitution reactions with chlorine and complete combustion with excess oxygen. Which row about the two reactions is correct? (columns: condition for reaction…
Answer this question and get it marked →What is used to identify the end-point of an acid-base titration? A balance B measuring cylinder C indicator D volumetric pipette
Answer this question and get it marked →Four pure substances, P, Q, R and S, are tested using chromatography. The same solvent is used each time. The table shows the distance moved by each substance and by the solvent…
Answer this question and get it marked →A substance is tested with three different reagents. Which row shows the results obtained with aqueous iron(II) nitrate? (columns: aqueous sodium hydroxide; acidified aqueous…
Answer this question and get it marked →A student carries out a flame test on a sample. The flame colour observed is light green. Which ion is present in the sample? A Ba²⁺ B Ca²⁺ C Li⁺ D K⁺
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