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
41–50 of 57 · Normal
Question 41
1 mark · Normal
Answer and check →Why is unreacted ethene recycled in the hydration process for making ethanol?
- A.To save costs by heating less gas
- B.To maximise the total yield of ethanol from starting material
- C.To produce a more concentrated ethanol solution
- D.To use less catalyst in the process
Question 42
2 marks · Normal
Answer and see the solution →Give the names of the two reactants required to make ethanol by the hydration of ethene. Write the chemical formula for each.
Question 43
4 marks · Normal
Answer and see the solution →(a)[2 marks]List the three main conditions (temperature, pressure, and catalyst) used for the industrial hydration of ethene to make ethanol.
(b)[1 mark]State why a phosphoric acid catalyst is used in this process.
(c)[1 mark]Explain why the pressure used is not even higher than 70 atmospheres, even though increasing pressure can raise yield.
Question 44
3 marks · Normal
Answer and see the solution →Ethanol can be made from ethene by hydration.
(a)[1 mark]State the word equation for the hydration of ethene to produce ethanol.
(b)[2 marks]Write the balanced symbol equation for this reaction. Include physical states.
Question 45
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 46
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 47
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 48
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 49
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 50
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.