Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Alcohols
130 practice questions
Topics covered
- Drawing and naming the alcohols21 practice questions
- Ethanol burns in air19 practice questions
- Ethanol can be oxidised by heating with potassium dichromate(VI) in dilute sulfuric acid21 practice questions
- Making ethanol by fermentation19 practice questions
- Making ethanol by the hydration of ethene19 practice questions
- Comparing the two methods of producing ethanol20 practice questions
Practice questions
51–57 of 57 · Normal
Question 51
3 marks · Normal
Answer and see the solution →Ethanol is used as a fuel in some countries and can be produced either by fermentation or by hydration of ethene.
Explain, using your knowledge of resources and processing, why some countries may switch from hydration of ethene to fermentation to produce ethanol in the future.
Question 52
4 marks · Normal
Answer and see the solution →The table below gives information about two methods of making ethanol.
Comparison of Ethanol Production Methods Feature Fermentation Hydration of Ethene Raw material Corn or sugar cane (renewable) Ethene from crude oil (non-renewable) Process type Batch, slow Continuous, fast Energy requirement Low High Product purity Impure, needs further processing Very pure (a)[2 marks]Based on the table, give two reasons why a country with limited access to crude oil and plenty of farmland might prefer fermentation to make ethanol.
(b)[1 mark]Give one disadvantage to this country of using fermentation rather than hydration of ethene.
(c)[1 mark]Suggest one way the country could improve the efficiency of ethanol production using fermentation.
Question 53
3 marks · Normal
Answer and see the solution →A factory can produce ethanol by either fermentation or hydration of ethene. Each method has a different efficiency and energy requirement, as shown in the table below.
Method Percentage Yield (%) Energy Input per Tonne Ethanol (kJ) Fermentation 60 2,500 Hydration of ethene 95 6,000 (a)Calculate the amount of ethanol (in tonnes) produced from 1000 tonnes of raw material by each method.
(i)[1 mark]Fermentation
(ii)[1 mark]Hydration of ethene
(b)[1 mark]Which method requires less energy per tonne of ethanol produced? Show how you use the data to decide.
Question 54
6 marks · Normal
Answer and see the solution →Ethanol is an important organic compound with many uses, including as a fuel and a chemical feedstock.
(a)[1 mark]Describe one observable colour change when ethanol is oxidised by heating with potassium dichromate(VI) in dilute sulfuric acid.
(b)[1 mark]Write a word equation for the oxidation reaction described in part (a).
(c)[2 marks]State the role of sulfuric acid in this oxidation reaction.
(d)[2 marks]Describe how ethanol can be produced by fermentation.
Question 55
6 marks · Normal
Answer and see the solution →A student carries out two experiments: (A) heating ethanol with potassium dichromate(VI) in dilute sulfuric acid, and (B) producing ethanol by fermentation.
(a)[1 mark]In experiment A, state the colour change that occurs when ethanol is successfully oxidised.
(b)[1 mark]Name the final organic product formed in experiment A.
(c)[1 mark]In experiment B, yeast is added to a sugar solution. State one condition required to maximise ethanol production by fermentation.
(d)[3 marks]Complete the table below for each experiment.
Experiment Reactants Product A B Question 56
6 marks · Normal
Answer and see the solution →The two main industrial sources of ethanoic acid are laboratory oxidation of ethanol and microbial fermentation to produce ethanol. The steps below investigate both processes.
(a)[3 marks]A laboratory technician oxidises 4.6 g of ethanol (CH2OH, molar mass = 46 g/mol) using excess potassium dichromate(VI) in dilute sulfuric acid as the oxidising agent. Calculate the maximum mass of ethanoic acid (COOH, molar mass = 60 g/mol) that could be obtained.
(b)[1 mark]Explain the role of dilute sulfuric acid in the oxidation of ethanol with potassium dichromate(VI).
(c)[2 marks]Another technician produces ethanol by fermentation. State the conditions required for the fermentation of glucose to produce ethanol.
Question 57
6 marks · Normal
Answer and see the solution →Ethanol can be prepared by fermentation or it can be oxidised in the laboratory.
(a)Describe how ethanol can be oxidised using potassium dichromate(VI) in dilute sulfuric acid. Include what you would observe during the process.
(i)[1 mark]Describe the method used, including reagents and condition.
(ii)[1 mark]State the observable colour change that shows oxidation has occurred.
(iii)[1 mark]Name the organic product formed.
(b)Explain how ethanol can be produced by fermentation. Include two conditions that are essential for this process.
(i)[1 mark]State the process used and the starting material.
(ii)[2 marks]Give two conditions that ensure ethanol is produced, not other products.