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
11–20 of 21
Question 11
3 marks · Normal
Answer and see the solution →Ethanol is sometimes used to make vinegar by oxidation. Explain, in terms of the laboratory process, how a chemist could use potassium dichromate(VI) and dilute sulfuric acid to produce ethanoic acid from ethanol.
Question 12
4 marks · Normal
Answer and see the solution →The table shows the initial and final colours observed when ethanol is heated with potassium dichromate(VI) and dilute sulfuric acid.
Observation of Colour Changes during Oxidation Test Initial colour Final colour A Orange Green B Orange Orange C Orange Green Explain what has happened in each test. Suggest a reason why the outcome was different in test B.
Question 13
1 mark · Normal
Answer and check →Which statement best explains the role of dilute sulfuric acid in the oxidation of ethanol with potassium dichromate(VI)?
- A.It provides hydrogen ions needed for the reaction.
- B.It acts as a catalyst for ethanol oxidation.
- C.It reacts with ethanol to make ethene.
- D.It neutralises the potassium dichromate(VI).
Question 14
2 marks · Normal
Answer and see the solution →State the reagents and conditions required to oxidise ethanol to ethanoic acid in the laboratory.
Question 15
4 marks · Normal
Answer and see the solution →(a)[1 mark]What is the appearance of the potassium dichromate(VI) solution before ethanol is added?
(b)[2 marks]Describe the appearance of the solution after heating with ethanol.
(c)[1 mark]What does the observed colour change indicate about the reaction?
Question 16
2 marks · Normal
Answer and see the solution →Describe what happens to ethanol when it is heated with potassium dichromate(VI) in dilute sulfuric acid. Include what is formed in the reaction.
Question 17
4 marks · Normal
Answer and see the solution →(a)[1 mark]State the initial colour of potassium dichromate(VI) solution before ethanol is added and heated.
(b)[2 marks]Describe the colour change observed when ethanol is oxidised by heating with potassium dichromate(VI) in dilute sulfuric acid.
(c)[1 mark]Name the ion that causes the final colour observed.
Question 18
3 marks · Normal
Answer and see the solution →A student plans to oxidise ethanol using potassium dichromate(VI) in dilute sulfuric acid. Explain, with reasoning, the role of the sulfuric acid in this reaction and what would happen if it was not included.
Question 19
2 marks · Hard
Answer and see the solution →Describe what happens when ethanol is heated with potassium dichromate(VI) in dilute sulfuric acid. In your answer, name the organic product and state the type of chemical change occurring.
Question 20
5 marks · Hard
Answer and see the solution →(a)[1 mark]A student adds ethanol to a solution of potassium dichromate(VI) in dilute sulfuric acid. She then heats the mixture in a water bath.
State the initial colour of the potassium dichromate(VI) solution before the ethanol is added and heated.
(b)[2 marks]Describe the colour change observed as the reaction occurs and explain what causes this change.
(c)[1 mark]Which ion is responsible for the green colour observed at the end of the reaction?
(d)[1 mark]Explain why the colour change provides evidence that a redox reaction has taken place.