Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
71–80 of 133 · Hard
Question 71
2 marks · Hard
Answer and see the solution →Draw the displayed formula for propan-2-ol. Clearly show all atoms and bonds, including the –OH group.
Question 72
5 marks · Hard
Answer and see the solution →The molecule with the structural formula CH3CH2CH2OH is an alcohol.
(a)[1 mark]State the IUPAC name for this alcohol.
(b)[4 marks]Justify your answer by explaining the naming process step by step, referring to the features of the molecule.
Question 73
2 marks · Hard
Answer and see the solution →State the molecular formula for butan-1-ol. Then, state the number of carbon atoms in a molecule of butan-1-ol.
Question 74
2 marks · Hard
Answer and see the solution →Describe what would be observed if ethanol vapour is passed over heated copper(II) oxide, and state the type of reaction taking place.
Question 75
5 marks · Hard
Answer and see the solution →A student investigates the combustion of ethanol and oxidation by potassium dichromate. Study the following information and answer the questions that follow.
(a)[1 mark]Write the structural formula of ethanol.
(b)[2 marks]Ethanol burns completely in air. Name the two products formed in this reaction and state whether this reaction is exothermic or endothermic.
(c)[2 marks]Describe what is observed when ethanol is warmed with acidified potassium dichromate(VI) solution.
Question 76
2 marks · Hard
Answer and see the solution →Explain why water is always formed as a product when any alcohol burns completely in air.
Question 77
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 78
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.
Question 79
2 marks · Hard
Answer and see the solution →Explain why dilute sulfuric acid must be present when potassium dichromate(VI) is used to oxidise ethanol. Include in your answer the role that the acid plays in the reaction.
Question 80
2 marks · Hard
Answer and see the solution →State two reasons why anaerobic conditions are important during the fermentation of glucose to make ethanol.