Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Esters
68 practice questions
Topics covered
Practice questions
11–20 of 28 · Normal
Question 11
3 marks · Normal
Answer and see the solution →Esters are added to both food and perfumes.
Explain why esters are suitable for use in each of these products. Give a reason for each use.
Question 12
4 marks · Normal
Answer and see the solution →Table 1 shows the common smells of some esters.
Common smells of esters Ester Smell Methyl butanoate Apple Ethyl butanoate Pineapple Propyl ethanoate Pear Pentyl ethanoate Banana (a)[1 mark]State which ester would be suitable to add a pear flavour to a drink.
(b)[1 mark]Give one reason why esters are used in food flavourings.
(c)[1 mark]A manufacturer wants to create a banana-flavoured sweet. Name the ester they should use.
(d)[1 mark]Suggest why perfumes often contain a mixture of esters.
Question 13
1 mark · Normal
Answer and check →Which of the following is a typical use of esters?
- A.As a food flavouring
- B.To increase the melting point of metals
- C.As a source of carbon dioxide
- D.To make fertilisers
Question 14
2 marks · Normal
Answer and see the solution →State two reasons why esters are added to food and drinks.
Question 15
4 marks · Normal
Answer and see the solution →A chemist is developing a new perfume with a fruity scent.
(a)[1 mark]Suggest why esters are often used in making perfumes.
(b)[1 mark]State one property of esters that helps the scent of a perfume spread easily.
(c)[1 mark]Other than perfumes, name one use of esters.
(d)[1 mark]Explain how the use of esters benefits manufacturers of food products.
Question 16
3 marks · Normal
Answer and see the solution →Esters are widely used in everyday products.
(a)[1 mark]State one use of esters as a flavouring in the food industry.
(b)Perfume manufacturers often use mixtures including esters.
(i)[1 mark]State why esters are useful in perfumes.
(c)[1 mark]A chemist designs an artificial pear flavour. Estimate how many individual esters, from the following list, could be combined for this purpose: ethyl ethanoate, methyl butanoate, propyl ethanoate, and butyl methanoate.
Question 17
2 marks · Normal
Answer and see the solution →State the name of the acid catalyst used in the laboratory preparation of esters, and explain why direct heating with a Bunsen burner should not be used in this experiment.
Question 18
4 marks · Normal
Answer and see the solution →(a)[1 mark]Give the names of the starting alcohol and carboxylic acid used to prepare propyl ethanoate in the laboratory.
(b)[2 marks]Briefly describe the steps you would take to make a small sample of propyl ethanoate, including any safety precautions.
(c)[1 mark]State how you would detect the formation of propyl ethanoate after the reaction.
Question 19
4 marks · Normal
Answer and see the solution →The table shows results from making esters by reacting different combinations of carboxylic acids and alcohols using the laboratory method described.
Combinations of acids and alcohols used to make esters Carboxylic acid Alcohol Ester layer observed? Odour Ethanoic acid Ethanol Yes Sweet, fruity Ethanoic acid Propan-1-ol Yes Pear drop Butanoic acid Ethanol Yes Sweet, fruity Propanoic acid Propan-1-ol No - (a)[1 mark]Suggest a reason why no ester layer was observed in the last experiment, compared to the others.
(b)[1 mark]State one observation that would indicate an ester had formed in the other experiments.
(c)[2 marks]In the experiment where ethanoic acid and propan-1-ol were used, what extra precaution should be taken when smelling the product? Explain your answer.
Question 20
1 mark · Normal
Answer and check →Which one of these is an essential safety step when preparing esters in the laboratory?
- A.Smell the product directly from the top of the beaker
- B.Wear safety goggles throughout the experiment
- C.Heat the mixture using a strong Bunsen flame
- D.Add all the reactants together before mixing