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
651–660 of 991
Question 651
1 mark · Normal
Answer and check →Which statement best explains why ionic compounds, such as sodium chloride, are often crystalline?
- A.Because their ions are free to move in the lattice.
- B.Because the ions are arranged in a regular repeating pattern.
- C.Because they are made up of molecules.
- D.Because they contain only one type of atom.
Question 652
2 marks · Normal
Answer and see the solution →State what is meant by a 'giant ionic lattice' as found in sodium chloride.
Question 653
4 marks · Normal
Answer and see the solution →(a)[2 marks]Explain why a large amount of energy is required to melt an ionic compound such as sodium chloride.
(b)[2 marks]Compare the melting points of sodium chloride and potassium chloride. Both are ionic, but sodium chloride melts at 801 °C and potassium chloride at 770 °C. Suggest a reason for this difference.
Question 654
3 marks · Normal
Answer and see the solution →A student looks at two samples of different ionic compounds under a microscope. Sample A forms visible cube-shaped grains, but Sample B appears as a fine white powder and individual grains are not visible to the naked eye.
Using ideas about the arrangement of ions, calculate and explain how the crystalline property of ionic compounds is demonstrated in both samples.
Question 655
4 marks · Normal
Answer and see the solution →Two ionic compounds, sodium chloride (NaCl) and magnesium oxide (MgO), have the following melting points:
Compound Melting Point (°C) NaCl 801 MgO 2852 Analyse the data. Explain why magnesium oxide has a much higher melting point than sodium chloride. Your answer should consider the type of particles and the forces between them.
Question 656
2 marks · Hard
Answer and see the solution →Explain, in terms of the forces present, why ionic compounds such as sodium chloride have high boiling points.
Question 657
5 marks · Hard
Answer and see the solution →Crystals of sodium chloride are often seen as large, regular cubes under the microscope.
(a)[1 mark]State what is meant by the term 'crystalline' when describing a substance.
(b)[2 marks]Describe the arrangement of ions in the giant ionic lattice of sodium chloride as it relates to its crystalline appearance.
(c)[2 marks]Explain why the regular arrangement of ions results in sodium chloride crystals having a regular shape.
Question 658
2 marks · Hard
Answer and see the solution →Describe the arrangement of sodium and chloride ions in the giant ionic lattice of sodium chloride.
Question 659
1 mark · Easy
Answer and see the solution →State why potassium chloride conducts electricity when it is dissolved in water.
Question 660
3 marks · Easy
Answer and see the solution →The table shows three ionic compounds in different states:
States of ionic compounds Compound State Sodium chloride Solid Magnesium bromide Molten Potassium nitrate Aqueous (a)[1 mark]Which compound(s) in the table will conduct electricity? State all correct answers.
(b)[1 mark]State the condition required for any ionic compound to conduct electricity.
(c)[1 mark]Give one example from the table where the ionic compound will not conduct electricity, and state why.