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
291–300 of 423 · Normal
Question 291
6 marks · Normal
Answer and see the solution →This question is about the bonding and formulae for lithium fluoride and calcium chloride.
(a)[2 marks]Draw a dot-and-cross diagram to show the ionic bonding in lithium fluoride.
(b)[2 marks]Explain, using ion charges, why the formula for calcium chloride is .
(c)[2 marks]Write the formula for ammonium sulfate.
Question 292
6 marks · Normal
Answer and see the solution →This question is about the bonding and formulae of calcium chloride and other ionic compounds.
(a)[3 marks]Draw a dot-and-cross diagram to show the ionic bonding in calcium chloride ().
(b)[1 mark]State the electronic configuration of a chloride ion.
(c)[2 marks]Write the formula for copper(II) nitrate.
Question 293
6 marks · Normal
Answer and see the solution →This question is about explaining ionic bonding using calcium chloride and applying rules to deduce formulae for ionic compounds.
(a)[3 marks]Explain, in terms of electron transfer and ion formation, how calcium chloride () forms from its elements.
(b)[2 marks]Sodium oxide is another ionic compound. Write its formula and justify your answer using the charges on the ions.
(c)[1 mark]Copper(II) sulfate contains Cu2+ and SO4^2− ions. Explain why the correct formula is CuSO4.
Question 294
6 marks · Normal
Answer and see the solution →This question is about calcium chloride and how to write the formula for ionic compounds.
(a)[3 marks]Draw a dot-and-cross diagram to show how the electrons are arranged in calcium chloride (CaCl₂). Clearly show all outer shell electrons and use a key to show electrons from different atoms.
(b)[3 marks]Magnesium reacts with oxygen to form magnesium oxide. Write the formula for magnesium oxide and explain how you worked it out.
Question 295
2 marks · Normal
Answer and see the solution →State what is meant by a covalent bond. Explain the mechanism by which a covalent bond forms between two atoms.
Question 296
4 marks · Normal
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]State the number of bonding pairs and lone pairs of electrons on the nitrogen atom in ammonia.
Question 297
3 marks · Normal
Answer and see the solution →Ethene (CH) is an organic molecule. Explain, using electron arrangement, how you can use a dot-and-cross diagram to confirm that each atom in ethene has a full outer shell.
Question 298
4 marks · Normal
Answer and see the solution →Table 1. Molecules and their covalent bonds Molecule Number of Covalent Bonds per Molecule H2 1 CH4 4 NH3 3 CO2 4 Using the data in Table 1, answer the following questions:
(a)[1 mark]Which molecule contains the greatest number of covalent bonds per molecule?
(b)[2 marks]Explain why CO has four covalent bonds per molecule.
(c)[1 mark]State how many covalent bonds exist in two molecules of ammonia (NH).
Question 299
1 mark · Normal
Answer and check →Which of the following dot-and-cross diagrams correctly represents the covalent bonding in a molecule of hydrogen chloride, HCl?
- A.A. H and Cl with one shared pair and Cl with 6 additional outer electrons.
- B.B. H and Cl with one shared pair and Cl with only 2 outer electrons.
- C.C. H and Cl with two shared pairs between them.
- D.D. H atom with two electrons, Cl atom with seven electrons, but none shared.
Question 300
2 marks · Normal
Answer and see the solution →Describe what happens to the electrons in the outer shells of two hydrogen atoms when they form a molecule of hydrogen, H.