IGCSE Chemistry (0620) — May–June 2023, Paper 23

40 questions · every question answerable online with instant point-by-point AI marking against the official mark scheme.

Start with Question 1 →
Question 1 · 1 mark

Nitrogen is heated in a balloon, which expands slightly. Which statements about the molecules of nitrogen are correct? 1 They move further apart. 2 They move more quickly. 3 They…

Answer this question and get it marked →
Question 2 · 1 mark

The diagrams represent some elements, compounds and mixtures. 1 2 3 4 Which row describes the numbered substances? 1 2 3 4 A element mixture of compounds compound mixture of…

Answer this question and get it marked →
Question 3 · 1 mark

Two atoms, X and Y, have the same mass number but different atomic numbers. Which statement about X and Y is correct? A They have the same number of protons. B They have the same…

Answer this question and get it marked →
Question 4 · 1 mark

A sample of pure iron contains three isotopes only. percentage abundance isotope of isotope / % 2 n Fe 6 Fe 92 Fe The iron in the sample has a relative atomic mass of 55.9. What…

Answer this question and get it marked →
Question 5 · 1 mark

Magnesium oxide is a white solid at room temperature and pressure. Part of the structure of solid magnesium oxide is shown. key = Mg2+ magnesium ion = O2– oxide ion Three…

Answer this question and get it marked →
Question 6 · 1 mark

In which molecule are all the outer-shell electrons involved in covalent bonding? A Cl 2 B CH4 C HCl D NH3

Answer this question and get it marked →
Question 7 · 1 mark

Which row describes the properties of silicon(IV) oxide? giant covalent melting point structure A no high B no low C yes high D yes low

Answer this question and get it marked →
Question 8 · 1 mark

Which row describes the structure of a solid metal and explains the property? structure of solid metal property of solid metal A lattice of negative ions conducts electricity…

Answer this question and get it marked →
Question 9 · 1 mark

What is the formula of potassium oxide? A P2O B PO2 C KO D K2O

Answer this question and get it marked →
Question 10 · 1 mark

A dilute aqueous solution of sodium bromide is electrolysed using inert electrodes. Which row identifies the product at the cathode and at the anode? cathode anode A bromine…

Answer this question and get it marked →
Question 11 · 1 mark

Aluminium is extracted by electrolysis, as shown. graphite anode steel case – + + – aluminium oxide dissolved in molten cryolite graphite cathode molten aluminium Which row shows…

Answer this question and get it marked →
Question 12 · 1 mark

The reaction pathway diagram for an exothermic reaction is shown. energy progress of reaction Which row identifies labels 1, 2, 3 and 4? 1 2 3 4 A reactants ΔH Ea products B…

Answer this question and get it marked →
Question 13 · 1 mark

The equation for the complete combustion of ethene is shown. C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(g) Some bond energies are listed. bond energy bond in kJ / mol C–H 412 C–C 348 C=C…

Answer this question and get it marked →
Question 14 · 1 mark

Magnesium reacts with hydrochloric acid to form magnesium chloride and hydrogen. Why does magnesium powder react faster than magnesium ribbon? A The magnesium atoms in the powder…

Answer this question and get it marked →
Question 15 · 1 mark

Which row shows the conditions used in the Contact process? pressure temperature catalyst / atm / °C A iron 2 100 B iron 200 450 C vanadium(V) oxide 2 450 D vanadium(V) oxide 200…

Answer this question and get it marked →
Question 16 · 1 mark

A student heats hydrated copper(II) sulfate. The blue crystals change to a white powder. How can the student reverse this reaction? A Add anhydrous copper(II) sulfate to the white…

Answer this question and get it marked →
Question 17 · 1 mark

Which reaction of hydrochloric acid is a redox reaction? A MgCO3 + 2HCl → MgCl 2 + H2O + CO2 B Mg(OH)2 + 2HCl → MgCl 2 + 2H2O C MgO + 2HCl → MgCl 2 + H2O D Mg + 2HCl → MgCl 2 + H2

Answer this question and get it marked →
Question 18 · 1 mark

Which oxide is amphoteric? A Al 2O3 B CaO C Na2O D SO2

Answer this question and get it marked →
Question 19 · 1 mark

Four statements about strong acids are listed. 1 They react with carbonates to form carbon dioxide. 2 They completely dissociate in aqueous solution. 3 They react with ammonium…

Answer this question and get it marked →
Question 20 · 1 mark

Which reaction mixture will produce a precipitate? A aqueous Na2CO3 and aqueous CuSO4 B dilute H2SO4 and aqueous NaOH C dilute HNO3 and solid MgO D solid CuO and dilute H2SO4

Answer this question and get it marked →
Question 21 · 1 mark

Which set of elements shows the change from metallic to non-metallic character across a period of the Periodic Table? A beryllium → magnesium → calcium B fluorine → bromine →…

Answer this question and get it marked →
Question 22 · 1 mark

A sample of ethanoic acid and a sample of hydrochloric acid have the same concentration. How do the hydrogen ion concentration and pH of ethanoic acid compare to those of…

Answer this question and get it marked →
Question 23 · 1 mark

What is a typical property of transition elements? A can act as catalysts B poor electrical conductivity C low melting point D low density

Answer this question and get it marked →
Question 24 · 1 mark

Which statement about copper or aluminium is correct? A Aluminium is more dense than copper. B Aluminium is less reactive than copper. C Copper has high ductility. D Copper has…

Answer this question and get it marked →
Question 25 · 1 mark

Water from a reservoir flows to the water works where purification process 1 takes place followed by process 2. What are processes 1 and 2? process 1 process 2 A chlorination…

Answer this question and get it marked →
Question 26 · 1 mark

Calcium reacts with cold water to produce hydrogen. Lead reacts slowly when heated in air to form an oxide but has almost no reaction with steam. Silver does not react with either…

Answer this question and get it marked →
Question 27 · 1 mark

Blocks of magnesium are attached to the bottom of a steel boat to prevent rusting. Which equation describes a change that prevents the steel from rusting? A Fe → Fe3+ + 3e– B…

Answer this question and get it marked →
Question 28 · 1 mark

Which statements about the extraction of iron in a blast furnace are correct? 1 The temperature inside the blast furnace is increased by burning carbon. 2 Iron(III) oxide is…

Answer this question and get it marked →
Question 29 · 1 mark

Which statements about water are correct? 1 Tap water has fewer impurities than distilled water. 2 Tap water will turn anhydrous cobalt(II) chloride pink. 3 The domestic water…

Answer this question and get it marked →
Question 30 · 1 mark

Oxides of nitrogen form in car engines and are removed by catalytic converters. Which equation represents a reaction that occurs in a catalytic converter? A CO + NO2 → NO + CO2 B…

Answer this question and get it marked →
Question 31 · 1 mark

An alkene is represented by the formula CH3CH=CH2. Which name is given to this type of formula? A displayed B empirical C general D structural

Answer this question and get it marked →
Question 32 · 1 mark

What is the structure of propanoic acid? A B H H O H H H O H C C C H C C C C H H OH H H H OH C D H H H H H H H H C C C OH H C C C C OH H H H H H H H

Answer this question and get it marked →
Question 33 · 1 mark

Butane reacts with chlorine in the presence of ultraviolet radiation. What is the equation for this reaction? A C4H10 + Cl 2 → C4H8Cl 2 + H2 B C4H10 + Cl 2 → C4H9Cl + HCl C C4H10…

Answer this question and get it marked →
Question 34 · 1 mark

A hydrocarbon P is cracked to make compound Q and hydrogen. Compound R is formed by the addition polymerisation of compound Q. To which homologous series do P, Q and R belong?…

Answer this question and get it marked →
Question 35 · 1 mark

Which substances are structural isomers? A but-2-ene and propene B ethyl ethanoate and butanoic acid C methyl methanoate and ethanol D propan-1-ol and butan-1-ol

Answer this question and get it marked →
Question 36 · 1 mark

Ethanol is produced by: 1 the catalytic addition of steam to ethene 2 fermentation. Which statement is correct? A Both processes use similar amounts of energy. B Both processes…

Answer this question and get it marked →
Question 37 · 1 mark

The two monomers shown can be used to form a condensation polymer. O H H H H O H H H H H H H H C C C C C C N C C C C C C N H O H H H H O H H H H H H H H H Which small molecule is…

Answer this question and get it marked →
Question 38 · 1 mark

Dilute hydrochloric acid is titrated into a conical flask containing sodium hydroxide solution and a few drops of methyl orange indicator. Which piece of apparatus is used to add…

Answer this question and get it marked →
Question 39 · 1 mark

The chromatogram obtained from a chromatography experiment on substance S is shown. 4.5 cm solvent front 4.7 cm S 6.0 cm baseline 1.8 cm What is the Rf value of S? A 0.39 B 0.46 C…

Answer this question and get it marked →
Question 40 · 1 mark

Element X burns in air to form an acidic gas that decolourises potassium manganate(VII). What is X? A carbon B nitrogen C magnesium D sulfur

Answer this question and get it marked →

← May–June 2023 Paper 31 · May–June 2023 Paper 22 →

← All IGCSE Chemistry (0620) past papers