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
281–290 of 407 · Easy
Question 281
5 marks · Easy
Answer and see the solution →Ionic bonding depends on the strong attraction between oppositely charged ions. Magnesium oxide and aluminium oxide are two examples.
(a)[1 mark]State the charge on the magnesium ion and on the oxide ion in magnesium oxide.
(b)[2 marks]Explain why the electrostatic attraction in magnesium oxide is stronger than in sodium chloride.
(c)[1 mark]Aluminium oxide has the formula . State the charge on the aluminium ion and the oxide ion.
(d)[1 mark]Calculate the total positive charge and the total negative charge present in one formula unit of .
Question 282
5 marks · Easy
Answer and see the solution →This question is about common ions and how they are formed, using magnesium oxide and calcium fluoride as examples.
(a)[1 mark]Write the formula and charge of the ion formed by a magnesium atom.
(b)[1 mark]Explain why oxygen forms an ion with a negative charge.
(c)[1 mark]Calcium fluoride has the formula . What is the charge on a fluoride ion?
(d)[1 mark]Describe how calcium forms its ion. Mention what happens to its electrons.
(e)[1 mark]Sodium and sulphur can also form ions. Give the formula and charge of the ion formed by sulphur.
Question 283
5 marks · Easy
Answer and see the solution →This question is about ionic bonding in magnesium oxide and aluminium nitride.
(a)[3 marks]Draw a dot-and-cross diagram to show the ionic bonding in magnesium oxide (MgO).
Include charges on the ions.
(b)[2 marks]Aluminium is in Group 3 and nitrogen is in Group 5.
Using your answer to part (a) as a guide, describe how ions are formed when aluminium reacts with nitrogen to form aluminium nitride (AlN).
Question 284
1 mark · Easy
Answer and see the solution →State the type of particles that are attracted to each other in a covalent bond.
Question 285
3 marks · Easy
Answer and see the solution →Chlorine exists as diatomic molecules ( Cl2 ).
(a)[2 marks]Draw a dot-and-cross diagram to show the covalent bonding in a molecule of chlorine (Cl2).
(b)[1 mark]How many electrons are shared between the two chlorine atoms?
Question 286
2 marks · Easy
Answer and see the solution →A phosphorus atom has 5 electrons in its outer shell. How many covalent bonds can it form in a molecule of phosphorus trichloride (PCl3)?
Question 287
2 marks · Easy
Answer and see the solution →Explain, using dot-and-cross diagrams, why a molecule of hydrogen fluoride (HF) contains only one covalent bond.
Question 288
3 marks · Easy
Answer and see the solution →Table 1 shows the number of outer shell electrons and covalent bonds formed by some elements.
Table 1. Covalent bonds and outer electrons Element Number of outer electrons Number of covalent bonds Hydrogen 1 ? Oxygen 6 ? Carbon 4 ? Nitrogen 5 ? Question 289
1 mark · Easy
Answer and see the solution →Draw a dot-and-cross diagram to show a single covalent bond between two bromine atoms in a Br2 molecule.
Question 290
3 marks · Easy
Answer and see the solution →A student claims: ‘All atoms in a covalent bond must supply one electron to the shared pair.’
(a)[2 marks]Is this statement always correct? Give a reason for your answer.
(b)[1 mark]State what a shared pair of electrons is called.