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
81–90 of 161 · Hard
Question 81
2 marks · Hard
Answer and see the solution →In a titration experiment, a student uses 15.0 cm³ of 0.150 mol/dm³ hydrochloric acid to neutralise a sodium carbonate solution. Calculate the number of moles of hydrochloric acid that were used. Give your answer to three significant figures.
Question 82
2 marks · Hard
Answer and see the solution →A student wants to completely neutralise 10.0 cm³ of 0.200 mol/dm³ nitric acid with sodium carbonate solution. The balanced equation for the reaction is:
Calculate the minimum volume, in cm³, of 0.100 mol/dm³ sodium carbonate solution required to react fully with the nitric acid.
Question 83
5 marks · Hard
Answer and see the solution →Calcium hydroxide solution reacts with hydrochloric acid according to the following balanced equation:
In a titration, 25.0 cm³ of hydrochloric acid solution of concentration 0.120 mol/dm³ is reacted completely with calcium hydroxide solution.
(a)[1 mark]Calculate the number of moles of HCl present in 25.0 cm³ of solution.
(b)[1 mark]Determine the number of moles of Ca(OH)₂ required to react with this amount of HCl.
(c)[2 marks]Given that the concentration of Ca(OH)₂ is 0.0800 mol/dm³, calculate the volume (in cm³) of Ca(OH)₂ solution that supplies this amount of Ca(OH)₂.
(d)[1 mark]Explain briefly why it is important to use the balanced equation when carrying out these calculations.
Question 84
2 marks · Hard
Answer and see the solution →A solution contains 0.00500 mol of a substance at a concentration of 0.250 mol/dm³.
Calculate the volume of this solution, in cm³, required to provide 0.00500 mol of the substance.
Question 85
7 marks · Hard
Answer and see the solution →Ammonium chloride reacts with sodium hydroxide according to the following equation:
A student adds 50.0 cm³ of 1.20 mol/dm³ sodium hydroxide solution to an excess of ammonium chloride solution in a flask at room temperature and pressure (rtp).
(a)[1 mark]Calculate the number of moles of sodium hydroxide added.
(b)[1 mark]Determine the maximum number of moles of ammonia gas (NH₃) that could be produced from this amount of sodium hydroxide.
(c)[2 marks]Calculate the volume (in cm³) of ammonia gas produced at rtp.
(d)[3 marks]The student wants to repeat the experiment but only collect 480 cm³ of ammonia gas at rtp. Calculate the minimum volume (in cm³) of 1.20 mol/dm³ sodium hydroxide solution required to produce this amount of ammonia gas.
Question 86
7 marks · Hard
Answer and see the solution →Calcium reacts with hydrochloric acid to produce hydrogen gas according to the following equation:
A student wants to produce exactly 600 cm³ of hydrogen gas at room temperature and pressure (rtp). The concentration of hydrochloric acid available is 0.500 mol/dm³.
(a)[1 mark]Calculate the number of moles of hydrogen gas required to produce 600 cm³ of gas at rtp.
(b)[1 mark]Calculate the number of moles of hydrochloric acid (HCl) needed to react to produce this amount of hydrogen gas.
(c)[3 marks]Calculate the volume (in cm³) of 0.500 mol/dm³ hydrochloric acid solution required to produce 600 cm³ of hydrogen gas.
(d)[2 marks]If the same volume of hydrogen gas (600 cm³) is to be produced, what is the corresponding volume (in cm³) at rtp if measured in dm³?
Question 87
7 marks · Hard
Answer and see the solution →A student reacts sodium carbonate solution with excess hydrochloric acid at room temperature and pressure (rtp). The equation for the reaction is:
The student wants to produce exactly 2.40 dm³ of carbon dioxide gas measured at rtp.
(a)[1 mark]Calculate the number of moles of carbon dioxide that occupy 2.40 dm³ at rtp.
(b)[1 mark]Using the chemical equation, determine the number of moles of sodium carbonate required to produce this volume of carbon dioxide.
(c)[3 marks]The student has 0.500 mol/dm³ sodium carbonate solution. Calculate the volume of this solution, in cm³, needed to provide the amount of sodium carbonate calculated in part b.
(d)[1 mark]State the conversion factor you would use to convert a volume in dm³ to cm³.
(e)[1 mark]Explain why the molar volume of a gas at rtp is used in this calculation.
Question 88
2 marks · Hard
Answer and see the solution →Describe how a dot-and-cross diagram can be used to show the formation of magnesium oxide (MgO) from magnesium and oxygen atoms. Your answer should include arrangements and charges.
Question 89
5 marks · Hard
Answer and see the solution →This question is about the ionic bonding in magnesium oxide (MgO).
(a)[1 mark]State which ions are present in magnesium oxide and what charges they carry.
(b)[2 marks]Explain in detail why there is a strong electrostatic force between these ions.
(c)[2 marks]Suggest, with a reason, how the strength of ionic bonding in magnesium oxide would change if the oxide ions were replaced by fluoride ions (F^-).
Question 90
2 marks · Hard
Answer and see the solution →State the ion formed when a magnesium atom loses electrons, and give its charge. What type of ion is this called?