Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Giant covalent structures
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →Describe the structure and bonding in graphite.
Question 2
4 marks · Normal
Answer and see the solution →The table shows some physical properties of diamond and graphite.
Physical properties of diamond and graphite Substance Melting point/°C Hardness Conducts electricity Diamond 3550 Very hard No Graphite 3600 Soft Yes (a)[2 marks]Explain, in terms of their structures and bonding, why diamond is much harder than graphite.
(b)[2 marks]Explain, in terms of bonding, why graphite conducts electricity but diamond does not.
Question 3
3 marks · Normal
Answer and see the solution →A student connects graphite, diamond and C60 fullerene electrodes into identical electric circuits. The student measures the current in each case:
Electrical current measured Substance Current/mA Diamond 0.0 Graphite 15.0 C60 fullerene 0.0 Question 4
3 marks · Normal
Answer and see the solution →C60 fullerene, diamond and graphite are all allotropes of carbon. Explain how the structure and bonding in C60 fullerene differs from that in diamond and graphite.
Question 5
4 marks · Normal
Answer and see the solution →The table shows the melting points and hardness for three forms of carbon.
Properties of carbon allotropes Allotrope Melting point/°C Hardness Diamond 3550 Very hard Graphite 3600 Soft C60 fullerene 280 Soft (a)[2 marks]Using only the data, identify which allotrope(s) have a giant covalent structure. Explain your reasoning.
(b)[2 marks]Using the data and your knowledge, explain why C60 fullerene has a lower melting point than graphite.
Question 6
1 mark · Normal
Answer and check →Which statement correctly compares the electrical conductivity of diamond, graphite, and C60 fullerene?
- A.Only graphite conducts electricity because it has delocalised electrons.
- B.Only diamond conducts electricity because it has a giant covalent structure.
- C.Diamond and C60 fullerene both conduct electricity, but graphite does not.
- D.All three conduct electricity equally well.
Question 7
2 marks · Normal
Answer and see the solution →Describe the bonding in diamond in terms of the arrangement of carbon atoms and the bonds formed.
Question 8
4 marks · Normal
Answer and see the solution →Diamond is a non-conductor of electricity and is very hard, while graphite is soft but conducts electricity.
(a)[2 marks]Explain, in terms of bonding and structure, why diamond does not conduct electricity.
(b)[2 marks]Explain, using bonding and the arrangement of atoms, why graphite is soft.