Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Comparing the two methods of producing ethanol
20 practice questions
Practice questions
1–9 of 9 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State one advantage and one disadvantage of producing ethanol by fermentation compared to the hydration of ethene.
Question 2
4 marks · Normal
Answer and see the solution →The table below gives some information about two industrial methods for making ethanol.
Fermentation Hydration of Ethene Batch process Continuous process Sugar beet or corn used Ethene from crude oil used Slower (days) Faster (hours) Low temperature and pressure High temperature and pressure (a)[1 mark]Give one reason why some countries prefer making ethanol by fermentation.
(b)[1 mark]State one process feature that makes hydration of ethene more efficient than fermentation.
(c)[2 marks]Explain why ethanol from fermentation needs further processing before it can be used as a chemical feedstock.
Question 3
3 marks · Normal
Answer and see the solution →A chemical company can produce ethanol by either fermentation or hydration of ethene.
(a)[1 mark]The hydration of ethene gives ethanol that is 99% pure by mass. If 5.0 tonnes of ethanol are made, calculate the mass of pure ethanol obtained.
(b)[1 mark]Fermentation produces ethanol that is only 90% pure by mass from the same 5.0 tonnes. Calculate the mass of pure ethanol produced.
(c)[1 mark]Based on your answers, explain one advantage of the hydration method.
Question 4
3 marks · Normal
Answer and see the solution →Ethanol can be produced industrially by fermentation or by hydration of ethene with steam.
(a)[2 marks]Explain why the hydration of ethene is not considered a sustainable process in the long term.
(b)[1 mark]State one environmental advantage of using fermentation instead.
Question 5
2 marks · Normal
Answer and see the solution →State one advantage and one disadvantage of producing ethanol by hydration of ethene rather than by fermentation.
Question 6
4 marks · Normal
Answer and see the solution →Ethanol can be produced industrially by fermentation or by hydration of ethene.
(a)[1 mark]State the raw material used in fermentation to produce ethanol.
(b)[1 mark]State one condition needed for the hydration of ethene to produce ethanol.
(c)[1 mark]Explain one reason why the production of ethanol by fermentation is considered more sustainable than hydration of ethene.
(d)[1 mark]State one reason why the hydration of ethene is more efficient than fermentation for making ethanol.
Question 7
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 8
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 9
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.