Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
61–70 of 161 · Hard
Question 61
2 marks · Hard
Answer and see the solution →The molecular formula of a hydrocarbon is found to be C6H12. State its empirical formula.
Question 62
5 marks · Hard
Answer and see the solution →An experiment is carried out to determine the formula of a hydrated salt, magnesium sulfate crystals, MgSO4·nH2O. The following results are obtained:
Measurement Mass / g Mass of empty crucible 28.60 Mass of crucible + hydrated salt before heating 30.88 Mass of crucible + salt after heating to constant mass (anhydrous MgSO4) 30.00 (Ar: Mg = 24, S = 32, O = 16, H = 1)
(a)[1 mark]Calculate the mass of water lost during heating.
(b)[2 marks]Calculate the number of moles of anhydrous magnesium sulfate (MgSO4) present after heating. (Show your working.)
(c)[2 marks]Determine the value of n in the formula MgSO4·nH2O. (Show your working.)
Question 63
2 marks · Hard
Answer and see the solution →Write the balanced chemical equation, including state symbols, for the reaction of solid sodium with water to form aqueous sodium hydroxide and hydrogen gas.
Question 64
2 marks · Hard
Answer and see the solution →A sealed glass tube at rtp contains 0.42 moles of sulfur dioxide gas, SO₂. Calculate the volume, in dm³, of sulfur dioxide gas in the tube at rtp.
Question 65
5 marks · Hard
Answer and see the solution →Zinc reacts with dilute sulfuric acid to produce hydrogen gas according to the equation:
(a)[1 mark]State the volume, in dm³, occupied by 1 mole of hydrogen gas at rtp.
(b)[2 marks]Calculate the number of moles of hydrogen produced when 3.9 g of zinc reacts completely with excess sulfuric acid.
(Relative atomic mass: Zn = 65.)
(c)[2 marks]Calculate the volume, in dm³, of hydrogen gas produced at rtp from part (b).
Question 66
2 marks · Hard
Answer and see the solution →A sample of carbon monoxide, CO, has a volume of 6.0 dm³ at rtp. Calculate the number of moles of CO in the sample. Show your working.
Question 67
2 marks · Hard
Answer and see the solution →State the volume, in dm³ and in cm³, that 1 mole of a gas would occupy at room temperature and pressure (rtp).
Question 68
5 marks · Hard
Answer and see the solution →A student reacts zinc with dilute hydrochloric acid to produce hydrogen gas at room temperature and pressure (rtp), according to the equation:
The student collects exactly 0.85 mol of hydrogen gas.
(a)[2 marks]Calculate the volume, in dm³, of 0.85 mol of hydrogen gas at rtp. Show your working.
(b)[1 mark]Convert your answer from part (a) into cm³.
(c)[2 marks]Explain why a different gas produced under the same conditions and with the same number of moles would occupy the same volume.
Question 69
2 marks · Hard
Answer and see the solution →A laboratory sample has a measured volume of 0.275 dm³. Convert this volume to cm³, showing your working.
Question 70
2 marks · Hard
Answer and see the solution →A student collects 8.4 g of oxygen gas at room temperature and pressure (rtp). Calculate the volume, in dm³, of this oxygen gas. (Ar: O = 16; molar volume = 24 dm³ at rtp.)