Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
741–750 of 991
Question 741
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 742
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.
Question 743
2 marks · Hard
Answer and see the solution →Diamond is used for industrial cutting tools, while graphite is used as a lubricant. Explain, in terms of structure and bonding, why graphite can be used as a lubricant but diamond cannot.
Question 744
5 marks · Hard
Answer and see the solution →The three allotropes of carbon—diamond, graphite, and C60 fullerene—have different abilities to conduct electricity.
(a)[1 mark]State which, if any, of these allotropes can conduct electricity.
(b)[4 marks]For each allotrope, explain your answer by referring to their bonding and the movement of electrons.
Question 745
2 marks · Hard
Answer and see the solution →Describe the structure and bonding in C60 fullerene, referring to how carbon atoms are arranged and bonded in this allotrope.
Question 746
5 marks · Easy
Answer and see the solution →(a)[1 mark]Define a covalent bond.
(b)[2 marks]Explain, in terms of electrostatic attraction, how a covalent bond holds two atoms together.
(c)[1 mark]State one reason why many substances with simple molecular structures have low melting points.
(d)[1 mark]Methane, CH, is a gas at room temperature. Explain why, using your knowledge of bonding and structure.
Question 747
5 marks · Easy
Answer and see the solution →(a)[2 marks]Draw a dot-and-cross diagram to show the bonding in a molecule of hydrogen chloride (HCl).
(b)[1 mark]State how many covalent bonds are present in a molecule of hydrogen chloride.
(c)[2 marks]Chlorine is a gas at room temperature, but water (HO) is a liquid. Using ideas about relative molecular mass, explain this difference.
Question 748
5 marks · Easy
Answer and see the solution →(a)[2 marks]Hydrogen (H) and carbon dioxide (CO) are both covalent molecules. Calculate the relative molecular mass (M) of each molecule. (Relative atomic masses: H = 1, C = 12, O = 16)
(b)[2 marks]Which of these molecules would you expect to have a higher boiling point? Explain your answer in terms of molecular mass and intermolecular forces.
(c)[1 mark]State the type of bonding present in both hydrogen and carbon dioxide molecules.
Question 749
5 marks · Easy
Answer and see the solution →(a)[2 marks]Draw a dot-and-cross diagram to show the covalent bonding in a molecule of ammonia (NH).
(b)[2 marks]Explain why ammonia is a gas at room temperature, using your understanding of intermolecular forces.
(c)[1 mark]State how many lone pairs of electrons are present on the nitrogen atom in the ammonia molecule.
Question 750
6 marks · Normal
Answer and see the solution →This question is about covalent bonds and giant covalent structures.
(a)[2 marks]Define a covalent bond.
(b)[2 marks]Describe what holds the atoms together in a covalent bond.
(c)[2 marks]Diamond and graphite both contain carbon atoms joined by covalent bonds. State one way in which their structures are similar and one way in which they are different.