Chapter 7 (Mole Concepts and Stoichiometry)

© chiasamuel 2025 STUDENT NAME CLASS INDEX NUMBER Chpt 7: Mole Concepts and Stoichiometry MOCK PAPER READ THESE INSTRUCTIONS FIRST Write your centre number, index number and name on all the work you hand in. You may use an HB pencil for any diagrams, graphs or rough working. Write in dark blue or black pen. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. DO NOT WRITE ON ANY BARCODES. FOR EXAMINERS’ USE

© chiasamuel 2025 1 What is the volume of 3 mol of gas? A 24 dm³ B 48 dm³ C 72 dm³ D 96 dm³ 2 A sample of 2.0 g of sodium hydroxide is dissolved in 200 cm³ of water. What is the concentration of the solution? A 0.10 mol/dm³ B 0.25 mol/dm³ C 0.50 mol/dm³ D 1.00 mol/dm³ 3 If 0.25 mol of unknown element X has an atomic mass of 8, identify element X . A Helium B Sulfur C Germanium D Magnesium 4 The reaction below shows the extraction of iron from its oxide. 4H₂ (g) + Fe₃O₄ 3Fe (s) + 4H₂O (l) → If 2.16 g of water is produced from this reaction, what mass of iron is obtained from the extraction process? A 5.04 g B 6.10 g C 7.35 g D 8.12 g

© chiasamuel 2025 5 30 g of magnesium is gradually added to excess water. The equation for the reaction is as shown below. Mg + 2H₂O → Mg(OH)₂ + H₂ What is the mass of water that is used in this reaction? A 20 g B 30 g C 35 g D 40 g 6 (a) The relative atomic mass of fluorine is 19. What is the mass of 3 mol of fluorine gas? Mass: ………………… g [2] (b) What is the number of moles in a sample of 6.4 g of sulfur? Moles: ………………… mol [2] (c) 480 cm³ of hydrogen gas is formed as a result of a reaction. FInd the mass of the gas. Mass: ………………… g [2] [Total: 6]

© chiasamuel 2025 7 The following equation shows the reaction between sodium carbonate and hydrochloric acid. Na₂CO₃ (s) + 2HCl (aq) 2NaCl (aq) + CO₂ (g) + H₂O (l) → (a) One of the products, sodium chloride, has a state symbol, (aq). Define (aq). [1] (b) Find the number of moles, if 15.9 g of sodium carbonate is used in this reaction. Moles: ………………… mol [2] (c) What is the volume of carbon dioxide produced, measured at r.t.p.? Volume: ………………… dm³ [2] (d) What is the mass of water produced in this reaction? Mass: ………………… g [2] [Total: 7]

© chiasamuel 2025 8 In a reaction, zinc oxide is reacted with hydrochloric acid to form zinc chloride and water. (a) Wri