Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
The physical properties of ionic substances
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →Describe the arrangement of ions in the giant ionic lattice of sodium chloride.
Question 2
4 marks · Normal
Answer and see the solution →(a)[1 mark]State what holds the ions together in the lattice of an ionic compound such as sodium chloride.
(b)[2 marks]Explain, with reference to the lattice structure, why sodium chloride has a high melting point.
(c)[1 mark]Sodium chloride and magnesium oxide have similar lattice structures. Explain why magnesium oxide has a higher melting point.
Question 3
3 marks · Normal
Answer and see the solution →Explain why sodium chloride forms a giant ionic lattice instead of individual molecules. In your answer, refer to the charges on the ions and the overall structure.
Question 4
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 5
2 marks · Normal
Answer and see the solution →State what is meant by a 'giant ionic lattice' as found in sodium chloride.
Question 6
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 7
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 8
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.