Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Giant ionic structures
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →Sodium chloride is an ionic compound with a giant lattice structure.
State TWO properties of sodium chloride that are linked to its giant ionic lattice, and briefly explain why the lattice causes each property.
(a)[2 marks](b)[0 marks]Question 2
4 marks · Normal
Answer and see the solution →Magnesium oxide (MgO) is a typical giant ionic compound.
(a)[1 mark]State the ions present in magnesium oxide.
(b)[2 marks]Explain why magnesium oxide has a very high melting point.
(c)[1 mark]Describe what happens to the ions when solid magnesium oxide melts.
Question 3
3 marks · Normal
Answer and see the solution →Explain why giant ionic structures conduct electricity when molten but do not conduct when solid.
Question 4
4 marks · Normal
Answer and see the solution →The table below gives the melting points and ability to conduct electricity in the solid and molten states for some ionic compounds:
Melting points and conductivity of ionic compounds Compound Melting point (°C) Conducts electricity when solid? Conducts electricity when molten? Sodium chloride 801 No Yes Magnesium oxide 2852 No Yes Potassium bromide 734 No Yes (a)[1 mark]Which compound has the highest melting point?
(b)[2 marks]Suggest a reason why all three compounds do not conduct when solid.
(c)[1 mark]What allows these compounds to conduct when molten?
Question 5
1 mark · Normal
Answer and check →Which property best explains why potassium chloride has a high melting point?
- A.It consists of molecules joined by covalent bonds.
- B.Its ions are arranged in layers that slide past each other.
- C.It is made of positive and negative ions held by strong electrostatic forces.
- D.It has delocalised electrons that conduct electricity.
Question 6
2 marks · Normal
Answer and see the solution →Describe the structure of a giant ionic compound and explain how this structure is linked to its melting point.
Question 7
4 marks · Normal
Answer and see the solution →Calcium chloride is an ionic compound with the formula CaCl_2.
(a)[1 mark]Name the ions present in calcium chloride.
(b)[2 marks]Explain why calcium chloride is soluble in water but does not conduct electricity when solid.
(c)[1 mark]What must happen for solid calcium chloride to conduct electricity?
Question 8
3 marks · Normal
Answer and see the solution →A student is comparing the melting points and electrical conductivity of two compounds: sodium chloride (NaCl) and magnesium oxide (MgO).
(a)[1 mark]Sodium chloride melts at around 801°C, while magnesium oxide melts at about 2852°C. Calculate the difference in melting points between these two ionic compounds.
(b)[2 marks]Explain, using the structure and bonding in giant ionic lattice structures, why magnesium oxide has a much higher melting point than sodium chloride.