Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Why things conduct electricity
17 practice questions
Practice questions
1–10 of 17
Question 1
1 mark · Easy
Answer and see the solution →State whether solid potassium nitrate conducts electricity. Give your answer as 'yes' or 'no'.
Question 2
3 marks · Easy
Answer and see the solution →The table shows the state of three substances at room temperature:
(a)Substance State Calcium bromide Solid Ethanol Liquid Magnesium sulfate (aq) Solution (i)[1 mark]Which one of these substances is most likely to conduct electricity? State your answer.
(ii)[1 mark]State the type of particles that must be present and able to move for conduction to occur in this substance.
(iii)[1 mark]Explain why the other two substances do not conduct electricity at room temperature.
Question 3
2 marks · Easy
Answer and see the solution →Explain why molten potassium iodide conducts electricity, but solid potassium iodide does not.
Question 4
3 marks · Easy
Answer and see the solution →A student tests four different substances for electrical conductivity in different states. The results are shown below:
(a)Substance State Conducts electricity? Lead bromide Molten Yes Sucrose Solid No Potassium nitrate Aqueous solution Yes Silicon dioxide Solid No (i)[1 mark]Identify which substance is a covalent compound and give evidence from the table for your answer.
(ii)[1 mark]State the common feature of all the substances that do conduct electricity in this test.
(iii)[1 mark]Suggest why silicon dioxide does not conduct electricity.
Question 5
1 mark · Easy
Answer and see the solution →Does liquid ethanol conduct electricity? Answer 'yes' or 'no'.
Question 6
3 marks · Easy
Answer and see the solution →Water is added to solid lithium chloride until it dissolves.
(a)[1 mark]Predict whether lithium chloride solution conducts electricity.
(b)[2 marks]Explain why your answer is correct in terms of particle movement.
Question 7
2 marks · Normal
Answer and see the solution →Explain why solid sodium chloride does not conduct electricity, but sodium chloride solution does.
Question 8
4 marks · Normal
Answer and see the solution →(a)[1 mark]State the type of bonding found in magnesium chloride.
(b)[3 marks]Explain whether magnesium chloride conducts electricity when solid and when dissolved in water.
Question 9
3 marks · Normal
Answer and see the solution →A student wants to test the conductivity of three substances: solid calcium chloride, molten calcium chloride, and pure water.
For each substance, she sets up a circuit and measures the current flowing when a voltage of 6 V is applied.
Substance Current (A) Solid calcium chloride 0.00 Molten calcium chloride 1.45 Pure water 0.00 Calculate the total current measured for the substances that conduct electricity. Show your working.
Question 10
3 marks · Normal
Answer and see the solution →Ammonia, NH3, is a covalent compound. Predict whether ammonia conducts electricity in any state, and explain your reasoning.