Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Why things conduct electricity
17 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →Explain why solid sodium chloride does not conduct electricity, but sodium chloride solution does.
Question 2
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 3
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 4
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.
Question 5
4 marks · Normal
Answer and see the solution →(a)[2 marks]The table shows the results from testing four substances for electrical conductivity:
Substance State Conducts electricity? Potassium bromide Solid No Potassium bromide Molten Yes Glucose Solution in water No Potassium bromide Solution in water Yes Use the data to identify the substance(s) that conduct electricity and describe the conditions in which conduction occurs.
(b)[2 marks]Suggest a reason why potassium bromide conducts electricity in its molten state and in aqueous solution, but not as a solid.
Question 6
1 mark · Normal
Answer and check →Which statement best explains why sodium chloride solution conducts electricity?
- A.It contains ions that are free to move.
- B.It contains free electrons that carry charge.
- C.It contains molecules that can move around.
- D.It contains atoms that are free to move.
Question 7
4 marks · Normal
Answer and see the solution →(a)[2 marks]Explain why molten zinc chloride can conduct electricity but solid zinc chloride cannot.
(b)[2 marks]Describe what must be present in a substance for it to conduct electricity.
Question 8
2 marks · Normal
Answer and see the solution →Explain why solid sodium chloride does not conduct electricity, but molten sodium chloride does.