The mole and the Avogadro constant — Paper 2 · IGCSE Sciences - Co-ordinated (Double) 0654

17 Hydrogen chloride is a gas. It dissolves in water to form an acidic solution. Three different samples of hydrogen chloride are listed. 1 73.0 g of hydrogen chloride gas 2 7.30 dm3 of hydrogen chloride gas 3 730 cm3 of 1.00 mol / dm3 solution of hydrogen chloride Which row shows the relative number of moles of hydrogen chloride in these samples? fewest most A 1 2 3 B 1 3 2 C 2 3 1 D 3 2 1

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2018

18 The equation for the decomposition of copper carbonate is CuCO3(s) → CuO(s) + CO2(g) Which volume of carbon dioxide is produced when 0.10 mol of copper carbonate is decomposed? A 0.24 dm3 B 2.4 dm3 C 24 dm3 D 240 dm3

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2018

17 Which sample of gas contains the most molecules? A 2 g of hydrogen, H2 B 48 g of oxygen, O2 C 56 g of nitrogen, N2 D 64 g of sulfur dioxide, SO2

1 marks

Answer: C

This question in 0654/23 Oct/Nov 2018

17 The concentration of a sample of dilute sulfuric acid, H2SO4, is 0.01 mol / dm3. What is the mass of sulfuric acid in 1 dm3 of the sample? A 0.49 g B 4.9 g C 0.98 g D 9.8 g

1 marks

Answer: C

This question in 0654/22 May/June 2019

17 1 g of hydrogen contains 6 × 1023 atoms. The relative atomic mass of helium is 4. How many atoms does 1 g of helium contain? A 1.5 × 1023 B 2.4 × 1024 C 6 × 1023 D 2.4 × 1023

1 marks

Answer: A

This question in 0654/21 Oct/Nov 2019

17 Which sample does not contain two moles of hydrogen atoms? A Avogadro’s number of hydrogen molecules B 1 g of hydrogen molecules C 18 g of water molecules D 24 dm3 hydrogen molecules at room temperature and pressure

1 marks

Answer: B

This question in 0654/23 Oct/Nov 2019

16 What is the volume of 0.35 mol of hydrogen gas at room temperature and pressure? A 2.1 dm3 B 4.2 dm3 C 8.4 dm3 D 16.8 dm3

1 marks

Answer: C

This question in 0654/21 May/June 2020

16 The equation for the combustion of magnesium is shown. 2Mg + O2 → 2MgO What is the mass of magnesium oxide formed from 12 g of magnesium? A 20 g B 24 g C 40 g D 80 g

1 marks

Answer: A

This question in 0654/23 May/June 2020

16 The equation for the complete combustion of methane is shown. CH4 + 2O2  CO2 + 2H2O What is the mass of oxygen that is required for the complete combustion of 16 g of methane? A 8 g B 16 g C 32 g D 64 g

1 marks

Answer: D

This question in 0654/21 Oct/Nov 2020

16 Which sample contains the smallest number of moles of the substance? A 12 dm3 of hydrogen at room temperature and pressure B 500 cm3 of 0.5 mol / dm3 hydrochloric acid C 12 g of carbon D 20 g of calcium

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2020

15 Which sample contains the most molecules? A 16 dm3 CH4 B 28 dm3 C2H4 C 16 g CH4 D 28 g C2H4

1 marks

Answer: B

This question in 0654/23 Oct/Nov 2020

16 What is the mass of hydrogen in 51 g of ammonia, NH3? A 3 g B 9 g C 14 g D 17 g

1 marks

Answer: B

This question in 0654/22 Feb/March 2021

17 Which quantity contains one mole of the substance? A 6 g of carbon atoms, C B 12 dm3 of hydrogen gas, H2, at room temperature and pressure C 32 g of oxygen atoms, O D 44 g of carbon dioxide gas, CO2

1 marks

Answer: D

This question in 0654/23 May/June 2021

15 Carbon dioxide is produced in a reaction. It is collected in a gas syringe. The readings on the gas syringe are shown. reading / cm3 initial 7 final 43 What is the mass of carbon dioxide gas produced? A 0.0015 g B 0.0018 g C 0.0660 g D 0.0788 g

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2021

15 Hydrogen chloride is a gas. It dissolves in water to form an acidic solution. Three different samples of hydrogen chloride are listed. 1 73.0 g of hydrogen chloride gas 2 7.30 dm3 of hydrogen chloride gas at r.t.p. 3 730 cm3 of 1.00 mol / dm3 aqueous hydrogen chloride Which row shows the relative number of moles of hydrogen chloride in these samples? fewest most A 1 2 3 B 1 3 2 C 2 3 1 D 3 2 1

1 marks

Answer: C

This question in 0654/22 Feb/March 2022

17 1 g of hydrogen contains 6  1023 atoms. The relative atomic mass of helium is 4. How many atoms does 1 g of helium contain? A 1.5  1023 B 3  1023 C 6  1023 D 2.4  1024

1 marks

Answer: A

This question in 0654/21 Oct/Nov 2022

17 1 g of hydrogen contains 6  1023 atoms. The relative atomic mass of helium is 4. How many atoms does 1 g of helium contain? A 1.5  1023 B 3  1023 C 6  1023 D 2.4  1024

1 marks

Answer: A

This question in 0654/22 Oct/Nov 2022

17 1 g of hydrogen contains 6 × 1023 atoms. The relative atomic mass of helium is 4. How many atoms does 1 g of helium contain? A 1.5 × 1023 B 3 × 1023 C 6 × 1023 D 2.4 × 1024

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2022

16 Which statements about the mole are correct? 1 One mole of 12C contains twice as many atoms as one mole of 24Mg. 2 One mole of 12C has a mass of 12 g. 3 One mole of C contains Avogadro’s number of atoms. 4 One mole of oxygen gas at room temperature and pressure occupies 32 dm3. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: C

This question in 0654/22 Feb/March 2023

17 When magnesium carbonate reacts with dilute hydrochloric acid, carbon dioxide gas is released. The equation for this reaction is shown. MgCO3 + 2HCl  MgCl 2 + CO2 + H2O Which volume of carbon dioxide, collected at room temperature and pressure, is released when 4.2 g of magnesium carbonate reacts with excess dilute hydrochloric acid? A 1.2 dm3 B 2.4 dm3 C 4.8 dm3 D 12 dm3

1 marks

Answer: A

This question in 0654/21 Oct/Nov 2023

17 Nonane, C9H20, burns in oxygen to form carbon dioxide and water. The equation for this reaction is shown. C9H20 + 14O2  9CO2 + 10H2O What is the mass of oxygen required for the complete combustion of 64 g of nonane? A 32 g B 224 g C 396 g D 448 g

1 marks

Answer: B

This question in 0654/23 Oct/Nov 2023

16 In an experiment, 2.4 g of magnesium, Mg, is burned in 5.0 g of oxygen, O2. The equation for the reaction is shown. 2Mg + O2  2MgO Which row identifies the substance that reacts completely and shows the mass of magnesium oxide formed? mass of substance that magnesium oxide reacts completely formed / g A magnesium 4.0 B magnesium 7.4 C oxygen 4.0 D oxygen 7.4

1 marks

Answer: A

This question in 0654/22 Feb/March 2024

18 The equation for the combustion of magnesium is shown. 2Mg + O2  2MgO What is the mass of magnesium oxide formed from 12 g of magnesium? A 20 g B 24 g C 40 g D 80 g

1 marks

Answer: A

This question in 0654/21 May/June 2024

16 The equation for the reaction of sodium with water is shown. 2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g) Which mass of sodium produces 30 cm3 of hydrogen? A 0.0288 g B 0.0575 g C 28.8 g D 57.5 g

1 marks

Answer: B

This question in 0654/22 May/June 2024

15 A sample of methane has mass 16.0 g at r.t.p. and contains the Avogadro number of molecules. What is the volume of 4.0 g of methane at r.t.p.? A 4.0 dm3 B 6.0 dm3 C 16 dm3 D 24 dm3

1 marks

Answer: B

This question in 0654/23 Oct/Nov 2024

20 Which quantities, when measured at room temperature and pressure, contain one mole of oxygen molecules? 1 16 g of oxygen molecules 2 12 dm3 of oxygen molecules 3 the Avogadro constant number of oxygen molecules 4 24 dm3 of oxygen molecules A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

1 marks

Answer: D

This question in 0654/21 May/June 2025

15 Ammonia decomposes when heated in a sealed container in the presence of an iron catalyst. The equation for the reaction is shown. 2NH3(g)  N2(g) + 3H2(g) 40.0 dm3 of ammonia is heated. After several hours, 21.0 dm3 of hydrogen is present. The volumes are measured at r.t.p. What is the percentage of unreacted ammonia? A 35.0% B 47.5% C 52.5% D 65.0%

1 marks

Answer: D

This question in 0654/22 May/June 2025

20 Which statement about the Avogadro constant is correct? A It is the volume of 1 mole of a gas at room temperature and pressure. B It is the mass of 1 mole of a substance. C It is the number of particles in 1 mole of a substance. D It has a value of 24 dm3.

1 marks

Answer: C

This question in 0654/22 Oct/Nov 2025

21 Lead sulfate, PbSO4, is prepared by reacting lead oxide, PbO, with excess dilute sulfuric acid. The equation for the reaction is shown. PbO + H2SO4  PbSO4 + H2O What is the mass of lead oxide required to produce 22.6 g of lead sulfate? A 15.4 g B 16.6 g C 17.6 g D 17.8 g

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2025