Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
What would happen with non-electrolytes?
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →A student wants to know whether glucose (C6H12O6) is an electrolyte, an ionic compound, or a covalent compound. They attempt to pass an electric current through both solid glucose and glucose dissolved in water, but the bulb does not light up in either case.
State what type of substance glucose is and give a reason based on the results of the experiment.
Question 2
4 marks · Normal
Answer and see the solution →Two students investigate the ability of different substances to conduct electricity using the apparatus below.
(a)[2 marks]Complete the table below by identifying whether each substance is likely to conduct electricity or not in the form stated.
Substance State Will it conduct electricity? (Yes/No) Sodium chloride Molten Sucrose (C12H22O11) Aqueous solution (b)[2 marks]Explain why one of these substances does not conduct electricity in the given state.
Question 3
3 marks · Normal
Answer and see the solution →Water is often used as the solvent in electrolysis experiments. Pure water conducts electricity only very weakly, but when a small amount of sodium chloride is added, it conducts electricity much better.
Explain why pure water is a poor conductor of electricity and why adding sodium chloride increases the conductivity so much.
Question 4
4 marks · Normal
Answer and see the solution →The table below shows results from an experiment where a student measured the volume of oxygen gas produces at the anode when different substances are electrolysed:
Results of electrolysis Substance (aq) Bulb lights? Volume of O2 at anode (cm³) Sodium sulfate Yes 18.5 Copper(II) sulfate Yes 17.8 Sugar No 0 Ethanol No 0 (a)[2 marks]Identify which substances are electrolytes and which are non-electrolytes. Explain your choices.
(b)[2 marks]State what this experiment shows about the type of bonding in sugar and ethanol.
Question 5
1 mark · Normal
Answer and check →The student sets up an apparatus to test substance X for electrical conductivity. The bulb stays off, and even after substance X is dissolved in water, there is still no current. What does this suggest about substance X?
- A.It is an ionic compound that conducts electricity when solid.
- B.It is a covalent compound that forms ions in water.
- C.It is a non-electrolyte and does not produce ions in solution.
- D.It is an acid and must form ions in solution.
Question 6
2 marks · Normal
Answer and see the solution →Explain why potassium iodide (KI) will conduct electricity when molten but not as a solid.
Question 7
4 marks · Normal
Answer and see the solution →You are given a white solid (substance Y) that is soluble in water. You need to determine whether it is an ionic compound, a covalent compound, or a non-electrolyte.
(a)[2 marks]Describe an experiment you could do to determine the type of substance.
(b)[2 marks]State what you would observe if substance Y is an ionic compound and explain your answer.
Question 8
3 marks · Normal
Answer and see the solution →A student wants to find out whether substance X is an ionic compound, a covalent compound (non-electrolyte), or an acid using an experiment. She sets up the following experiment in which two carbon electrodes are placed in a solution of substance X, connected to a power supply and a bulb, as shown in the diagram:
Apparatus for testing conductivity. In three separate experiments she uses:
Test Substance in solution Observation A X dissolved in water Bulb does not light up B Molten X Bulb lights up C Aqueous acid Bulb lights up Using the data above, calculate whether substance X is ionic, covalent (non-electrolyte), or an acid. Explain your reasoning.