Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Covalent Bonding
68 practice questions
Topics covered
Practice questions
41–50 of 68
Question 41
2 marks · Easy
Answer and see the solution →Diamond has a melting point of about 3550 °C, while C60 fullerene melts at about 280 °C. Use these values to explain, in terms of bonding, why diamond has such a high melting point compared to C60 fullerene.
Question 42
2 marks · Easy
Answer and see the solution →Explain why C60 fullerene does not conduct electricity as well as graphite, referring to their structures.
Question 43
3 marks · Easy
Answer and see the solution →Bonding and Atomic Arrangement Carbon Allotrope Number of covalent bonds per carbon atom Type of structure Diamond Graphite C60 fullerene Complete the table by filling in the number of covalent bonds per carbon atom and the type of structure for each allotrope.
Question 44
1 mark · Easy
Answer and see the solution →State why graphite is soft.
Question 45
3 marks · Easy
Answer and see the solution →(a)[1 mark]State the electrical conductivity for each of the following carbon structures: diamond, graphite, and C60 fullerene.
(b)[1 mark]Explain why diamond does not conduct electricity.
(c)[1 mark]Explain why graphite conducts electricity.
Question 46
2 marks · Easy
Answer and see the solution →C60 fullerene contains 60 carbon atoms. If each carbon atom forms 3 bonds, calculate the total number of covalent bonds in one C60 molecule.
Question 47
2 marks · Normal
Answer and see the solution →Describe the structure and bonding in graphite.
Question 48
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 49
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 50
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.