Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Esters
68 practice questions
Topics covered
Practice questions
51–60 of 68
Question 51
2 marks · Normal
Answer and see the solution →State two reasons why sodium carbonate solution is added at the end of the ester preparation process.
Question 52
4 marks · Normal
Answer and see the solution →A chemistry student mixes methanol and butanoic acid to make an ester using the laboratory method.
(a)[1 mark]Name the ester formed.
(b)[2 marks]Briefly outline the apparatus set-up used for heating the reaction mixture safely.
(c)[1 mark]How would you test for the presence of the ester after the reaction is complete?
Question 53
3 marks · Normal
Answer and see the solution →A student prepares an ester in the lab by reacting 1.0 cm³ of propanoic acid (density = 1.01 g/cm³, molar mass = 74 g/mol) with an excess of methanol in the presence of a few drops of concentrated sulfuric acid. After the reaction, they transfer the contents to water to isolate the ester layer.
Calculate the maximum mass of methyl propanoate that could be formed from the propanoic acid used.
Question 54
3 marks · Normal
Answer and see the solution →Describe how esters can be made and separated in the laboratory. In your answer, explain the roles of each of the following:
(a) concentrated sulfuric acid,
(b) the hot water bath,
(c) adding sodium carbonate solution after the reaction.
Question 55
2 marks · Hard
Answer and see the solution →State the role of sulfuric acid in the laboratory preparation of an ester. Explain why only a few drops are added.
Question 56
5 marks · Hard
Answer and see the solution →A student is asked to prepare a sample of butyl propanoate, an ester, using only laboratory equipment and chemicals available at school.
(a)[1 mark]Write the names of the alcohol and the carboxylic acid required to make butyl propanoate.
(b)[3 marks]Describe, in order, the main steps the student should follow to prepare and purify butyl propanoate in the laboratory.
(c)[1 mark]State how the student can safely test for the smell of the product once separated.
Question 57
2 marks · Hard
Answer and see the solution →During the purification step in ester preparation, the mixture is poured into sodium carbonate solution. Explain the purpose of this step and describe what you would observe.
Question 58
5 marks · Easy
Answer and see the solution →Esters are made by reacting an alcohol with a carboxylic acid in the presence of an acid catalyst. They are used as flavourings and perfumes.
(a)[1 mark]Name the products when methanol reacts with ethanoic acid under suitable conditions.
(b)[2 marks]Draw the fully displayed structural formula of the ester formed in part (a).
(c)[1 mark]Give one common use of esters.
(d)[1 mark]Esters have a sweet smell. State whether this property makes them suitable for use as solvents, perfumes, or both. Explain your answer.
Question 59
5 marks · Easy
Answer and see the solution →Ethyl propanoate is an ester formed in organic chemistry reactions.
(a)[2 marks]Write the names of the alcohol and the carboxylic acid used to make ethyl propanoate.
(b)[1 mark]State one typical use for esters such as ethyl propanoate.
(c)[2 marks]Draw the structural formula for ethyl propanoate.
Question 60
5 marks · Easy
Answer and see the solution →The reaction between propanoic acid and methanol produces methyl propanoate and water.
(a)[2 marks]Write a balanced equation (using formulae) for the reaction of methanol and propanoic acid to form an ester.
(b)[1 mark]Name the ester formed in this reaction.
(c)[1 mark]Give one reason why esters are added to food and drink products.
(d)[1 mark]If 0.1 mol of propanoic acid and 0.1 mol of methanol are reacted, calculate the maximum amount (in mol) of ester that can be produced.