Pearson Edexcel International GCSE in Chemistry · 4CH1 · Free · no account needed
Ionic Structures and Their Properties — exam questions
12 original Incandio exam-style questions on Ionic Structures and Their Properties, 26 marks, about 26 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Ionic Structures and Their Properties — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
8 command words run through this set, and on Pearson Edexcel International GCSE Chemistry each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- State what is meant by (1–2 marks)
- the definition
- Name (1 mark)
- the correct chemical name
- Describe (2–5 marks)
- developed, linked statements of what happens or what is observed Misread as: giving one bare observation where the tariff asked for a developed account
- Explain (2–4 marks)
- the reason, in terms of particles, bonding, energy or equilibrium Misread as: describing the observation without giving the chemistry that causes it
- Suggest (1–3 marks)
- a plausible answer applying taught chemistry to an unfamiliar substance
- Identify (1–2 marks)
- the correct substance or feature selected from what is given
- Give a reason (1–2 marks)
- one reason — in chemistry this is a one-mark command
Assessed on Paper 1 (4CH1/1C) and Paper 2 (4CH1/2C), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Chemistry (4CH1) — statements 1.41 · 1.42 · 1.43. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 12 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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Table 1 — four solids tested for melting point and for electrical conduction Substance Melting point / °C Conducts as a solid Conducts when molten W −7 no no X 776 no yes Y 1085 yes yes Z 1610 no no (a)
(1)Identify
Identify the substance in Table 1 that has a giant ionic structure.
Table 1 — four solids tested for melting point and for electrical conduction Substance Melting point / °C Conducts as a solid Conducts when molten W −7 no no X 776 no yes Y 1085 yes yes Z 1610 no no (b)
(2)Give a reason
Give a reason for your choice, using two pieces of evidence from Table 1.
Table 1 — four solids tested for melting point and for electrical conduction Substance Melting point / °C Conducts as a solid Conducts when molten W −7 no no X 776 no yes Y 1085 yes yes Z 1610 no no (c)
(3)Explain
Explain, in terms of its particles, why substance X behaves differently as a solid and as a liquid in the last two columns of Table 1.
Table 1 — four solids tested for melting point and for electrical conduction Substance Melting point / °C Conducts as a solid Conducts when molten W −7 no no X 776 no yes Y 1085 yes yes Z 1610 no no (d)
(3)Suggest
Substance Y conducts in both states. Suggest what type of structure Y has, and why this makes it behave differently from X.
Table 1 — four solids tested for melting point and for electrical conduction Substance Melting point / °C Conducts as a solid Conducts when molten W −7 no no X 776 no yes Y 1085 yes yes Z 1610 no no (Total for Question 1 = 9 marks)
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(1)Which
Which describes the force that holds the ions together in an ionic compound?
Force A a shared pair of electrons B electrostatic attraction between oppositely charged ions C attraction between a nucleus and a sea of electrons D weak attraction between neighbouring molecules (Total for Question 2 = 1 mark)
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(1)State what is meant by
State what is meant by an ionic bond.
(Total for Question 3 = 1 mark)
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(1)Name
Name the type of structure formed when many oppositely charged ions pack together.
(Total for Question 4 = 1 mark)
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(2)Describe
Describe how the ions are arranged in a giant ionic lattice.
(Total for Question 5 = 2 marks)
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(3)Explain
Potassium iodide does not melt until 681 °C, while iodine melts at 114 °C. Explain this difference in terms of the structures of the two substances.
(Total for Question 6 = 3 marks)
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(2)Suggest
A crystal of an ionic compound shatters when it is struck sharply, rather than bending. Suggest why.
(Total for Question 7 = 2 marks)
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(3)Explain
An aqueous solution of potassium bromide conducts electricity. An aqueous solution of glucose does not. Explain why.
(Total for Question 8 = 3 marks)
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(4)Explain
Explain why sodium chloride will not conduct electricity as a solid but conducts well once it has melted.
(Total for Question 9 = 4 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 12 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Ionic Structures and Their Properties to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Michael Faraday over three rounds, marked against descriptors you can read first.
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Back to the lesson
- Ionic Structures and Their Properties — Why salt melts at 800 °C, why it will not conduct until it does, and why both facts come from the same lattice.
- All of Incandio Chemistry · Incandio Exam Practice