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
541–550 of 991
Question 541
6 marks · Normal
Answer and see the solution →A student reacts excess magnesium ribbon with 100 cm³ of 2.0 mol/dm³ hydrochloric acid in a flask at room temperature and pressure (rtp). Magnesium reacts with hydrochloric acid as follows:
(a)[2 marks]Calculate the amount, in moles, of hydrochloric acid present in 100 cm³ of 2.0 mol/dm³ HCl.
(b)[3 marks]Calculate the maximum volume, in cm³, of hydrogen gas produced at rtp.
(c)[1 mark]Suggest one reason why the actual volume of hydrogen collected might be less than this calculated value.
Question 542
6 marks · Normal
Answer and see the solution →A chemistry class investigates the reaction between solid calcium carbonate and dilute sulfuric acid. The reaction is:
(a)[2 marks]Explain why, after a short time, the reaction between calcium carbonate and dilute sulfuric acid slows down, even though there is still acid present.
(b)[2 marks]A student wants to calculate the concentration (in mol/dm³) of sulfuric acid if 5.0 g of CaCO3 is completely reacted using 250 cm³ of acid. (Ar: Ca = 40, C = 12, O = 16)
(c)[2 marks]The same student collects the carbon dioxide produced. Explain how they can use the volume of CO₂ collected at rtp to check if the reaction went to completion.
Question 543
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 544
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 545
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 546
1 mark · Easy
Answer and see the solution →What type of force holds the magnesium ions and oxide ions together in magnesium oxide?
Question 547
3 marks · Easy
Answer and see the solution →For the ionic compound magnesium oxide (MgO):
(a)[1 mark]State the charge of a magnesium ion.
(b)[1 mark]What is the charge on an oxide ion?
(c)[1 mark]Name the type of ion formed by magnesium.
Question 548
2 marks · Easy
Answer and see the solution →Draw a dot-and-cross diagram to show the electron arrangement in the Mg^{2+} ion. Use dots for magnesium's original electrons. Clearly show the charge.
Question 549
2 marks · Easy
Answer and see the solution →Explain why magnesium oxide has a high melting point. Use your knowledge of ionic bonding in your answer.
Question 550
3 marks · Easy
Answer and see the solution →The table shows the number of electrons in neutral atoms and the corresponding ions for magnesium and oxygen.
Particle Number of electrons Mg atom 12 Mg^{2+} ion O atom 8 O^{2-} ion (a)[2 marks]Complete the table by filling in the missing numbers for the ions.
(b)[1 mark]Explain, in terms of electron transfer, how these ions form.