Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Ethanol can be oxidised by heating with potassium dichromate(VI) in dilute sulfuric acid
21 practice questions
Practice questions
1–10 of 21
Question 1
1 mark · Easy
Answer and see the solution →State the initial colour of the potassium dichromate(VI) solution before ethanol is heated with it.
Question 2
3 marks · Easy
Answer and see the solution →(a)[2 marks]Explain why dilute sulfuric acid must be present for potassium dichromate(VI) to oxidise ethanol.
(b)[1 mark]State the role of sulfuric acid in this reaction.
Question 3
2 marks · Easy
Answer and see the solution →A student observes the colour change when ethanol is heated with potassium dichromate(VI) in dilute sulfuric acid. Explain why the green colour appears during this reaction.
Question 4
3 marks · Easy
Answer and see the solution →Results from three experiments on ethanol oxidation Experiment Potassium dichromate(VI) Dilute sulfuric acid Observed colour change 1 Yes Yes Orange to green 2 Yes No Orange, no change 3 No Yes Colourless, no change Using the data from the table, explain in terms of ions, the importance of dilute sulfuric acid for this experiment.
Question 5
1 mark · Easy
Answer and see the solution →Give the name of the organic product formed when ethanol is oxidised by heating with potassium dichromate(VI) in dilute sulfuric acid.
Question 6
3 marks · Easy
Answer and see the solution →(a)[1 mark]Describe the observable change in colour that occurs when ethanol is oxidised by heating with potassium dichromate(VI) in dilute sulfuric acid.
(b)[1 mark]What does this colour change indicate about the potassium dichromate(VI) during the reaction?
(c)[1 mark]Suggest what you would observe if the solution is heated without adding ethanol.
Question 7
2 marks · Easy
Answer and see the solution →Ethanol can be oxidised by heating it with potassium dichromate(VI) in dilute sulfuric acid.
Calculate the number of different substances (including ethanol and all reagents used) that must be present in the test-tube for this reaction to occur, according to standard laboratory practice.
Show your working.
Question 8
2 marks · Easy
Answer and see the solution →The oxidation of ethanol with potassium dichromate(VI) requires dilute sulfuric acid.
A chemist accidentally forgets to add any dilute sulfuric acid to the test-tube, while potassium dichromate(VI) and ethanol are both present.
Calculate the number of moles of H+ ions available to the reaction in this mistake, assuming none are present in the other reagents.
Show your working and state the reason for your answer.
Question 9
2 marks · Normal
Answer and see the solution →Describe what happens when ethanol is oxidised by heating it with potassium dichromate(VI) in dilute sulfuric acid.
Question 10
3 marks · Normal
Answer and see the solution →Explain, using your knowledge of acids and oxidation reactions, why dilute sulfuric acid is needed for potassium dichromate(VI) to oxidise ethanol.