Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Covalent Bonding
68 practice questions
Topics covered
Practice questions
11–20 of 28 · Easy
Question 11
2 marks · Easy
Answer and see the solution →Iodine melts at 114°C and boils at 184°C. Calculate the temperature range (in °C) over which iodine is a liquid.
Question 12
2 marks · Easy
Answer and see the solution →Explain why methane (CH₄) has a much lower boiling point than water (H₂O), using ideas about molecular mass and intermolecular forces.
Question 13
3 marks · Easy
Answer and see the solution →Examine the table below showing properties of some substances.
Properties of Substances Substance Structure Melting point (°C) Boiling point (°C) Oxygen simple molecular -219 -183 Graphite giant covalent 3930 4830 Sulphur dioxide simple molecular -73 -10 (a)[1 mark]Which substance in the table is likely to have the hardest structure? Give a reason.
(b)[2 marks]Explain why oxygen has a much lower melting point than graphite.
Question 14
1 mark · Easy
Answer and see the solution →State what happens to the boiling point of chlorine (Cl₂) as its relative molecular mass increases.
Question 15
3 marks · Easy
Answer and see the solution →Describe the structure and properties of a substance with a simple molecular structure.
(a)[1 mark]State the type of bonds within a simple molecule.
(b)[1 mark]Describe the forces between the molecules.
(c)[1 mark]Explain why these substances have low melting and boiling points.
Question 16
2 marks · Easy
Answer and see the solution →The melting point of fluorine is –220°C and its boiling point is –188°C. Calculate how many degrees fluorine is a liquid.
Question 17
1 mark · Easy
Answer and see the solution →State which form of carbon, out of diamond, graphite, and C60 fullerene, conducts electricity the best.
Question 18
3 marks · Easy
Answer and see the solution →(a)[1 mark]Describe the structure of diamond in terms of the arrangement of its carbon atoms.
(b)[1 mark]Describe the structure of graphite in terms of the arrangement of its carbon atoms.
(c)[1 mark]State the type of structure present in C60 fullerene.
Question 19
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 20
2 marks · Easy
Answer and see the solution →Explain why C60 fullerene does not conduct electricity as well as graphite, referring to their structures.