Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
The electrical conductivity of ionic substances
19 practice questions
Practice questions
1–8 of 8 · Easy
Question 1
1 mark · Easy
Answer and see the solution →State why potassium chloride conducts electricity when it is dissolved in water.
Question 2
3 marks · Easy
Answer and see the solution →The table shows three ionic compounds in different states:
States of ionic compounds Compound State Sodium chloride Solid Magnesium bromide Molten Potassium nitrate Aqueous (a)[1 mark]Which compound(s) in the table will conduct electricity? State all correct answers.
(b)[1 mark]State the condition required for any ionic compound to conduct electricity.
(c)[1 mark]Give one example from the table where the ionic compound will not conduct electricity, and state why.
Question 3
2 marks · Easy
Answer and see the solution →A student says that ‘solid lead(II) bromide contains charged particles, so it should conduct electricity’. Explain, giving a calculation or statement, why this is incorrect.
Question 4
2 marks · Easy
Answer and see the solution →Explain, in terms of ions, why calcium iodide conducts electricity when molten but not when solid.
Question 5
3 marks · Easy
Answer and see the solution →The table below shows whether four substances conduct electricity in different states.
Electrical conductivity of four substances Substance Solid Molten Aqueous Calcium Bromide No Yes Yes Iron(II) chloride No Yes Yes Sodium phosphate No Yes Yes Iodine No No No (a)[1 mark]From the substances in the table, identify all that are ionic compounds.
(b)[1 mark]What property do these ionic compounds share in relation to conducting electricity?
(c)[1 mark]Explain how the table helped you determine which substances are ionic.
Question 6
1 mark · Easy
Answer and see the solution →State why silver chloride does not conduct electricity in the solid state.
Question 7
3 marks · Easy
Answer and see the solution →Zinc chloride is an ionic compound.
(a)[1 mark]Describe the movement of ions in solid zinc chloride.
(b)[1 mark]Describe the movement of ions in molten zinc chloride.
(c)[1 mark]Explain how movement of ions in the molten state affects electricity conduction.
Question 8
2 marks · Easy
Answer and see the solution →Out of 5 ionic salts, 2 are molten, 1 is in aqueous solution, and the remaining 2 are solid. How many of these salts would you expect to conduct electricity? Show your working.