Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
651–660 of 785
Question 651
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 652
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 653
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.
Question 654
5 marks · Easy
Answer and see the solution →Esters such as propyl methanoate have distinctive smells and are made by reacting an alcohol with a carboxylic acid.
(a)[2 marks]State the name of the alcohol and the carboxylic acid used to form propyl methanoate.
(b)[2 marks]Draw the displayed formula of propyl methanoate, showing all atoms and bonds.
(c)[1 mark]State one use of esters such as propyl methanoate.
Question 655
6 marks · Normal
Answer and see the solution →Butanol and ethanoic acid are used together in a laboratory to produce an ester. Answer the following questions about this reaction and the practical steps involved.
(a)[1 mark]Name the ester formed in this reaction.
(b)[2 marks]Draw the structural formula for the ester you named in part (a).
(c)[1 mark]State the name of the catalyst used during this esterification reaction.
(d)[2 marks]Describe one step you would take in the laboratory to make the smell of the ester easier to detect after the reaction is complete.
Question 656
6 marks · Normal
Answer and see the solution →A student wants to prepare methyl propanoate in the laboratory using appropriate organic starting materials.
(a)[2 marks]Identify the alcohol and the carboxylic acid required to make methyl propanoate.
(b)[2 marks]Draw the structural formula for methyl propanoate.
(c)[2 marks]Describe briefly, in two steps, how a small sample of methyl propanoate can be prepared and the smell detected during a school practical.
Question 657
6 marks · Normal
Answer and see the solution →A group of students carried out an experiment to produce an ester from ethanol and propanoic acid. They left the product to stand after completing the practical.
(a)[2 marks]Explain how the students could confirm that an ester had formed, even if the reactants and product are colourless.
(b)[1 mark]Ethyl propanoate is an ester. Give the name of the alcohol used to manufacture this ester.
(c)[1 mark]The mixture was poured into a beaker containing sodium carbonate solution. Suggest a reason for this step.
(d)[2 marks]Explain why small esters are easy to separate from the reaction mixture compared to the carboxylic acid and alcohol used.
Question 658
6 marks · Normal
Answer and see the solution →Propanoic acid reacts with ethanol to form an ester. You are given 1.5 cm³ of propanoic acid (density = 1.00 g/cm³) and an excess of ethanol.
(a)[3 marks]Draw the structural formula of the ester formed in this reaction and name the ester.
(b)[2 marks]In a laboratory experiment, you attempt to prepare the ester in part (a). (i) Calculate the maximum mass of the ester that could be formed from 1.5 cm³ of propanoic acid (M_r of propanoic acid = 74, M_r of the ester = 102).
(c)[1 mark]Describe how you could separate and identify the smell of the ester after the reaction, referring to the laboratory method and your answer to part (b).
Question 659
7 marks · Hard
Answer and see the solution →Esters are formed from an alcohol and a carboxylic acid in an esterification reaction. Ethanol and butanoic acid react together under suitable conditions.
(a)[3 marks]Draw the full structural formula of the ester formed when ethanol reacts with butanoic acid.
(b)[1 mark]Name the ester formed in part (a).
(c)[1 mark]State one use of this ester in everyday life.
(d)[2 marks]Describe how esters like the one above are prepared in a laboratory. Include any catalyst and any condition needed.
Question 660
7 marks · Hard
Answer and see the solution →A student mixes methanol and propanoic acid in the presence of a few drops of concentrated sulfuric acid and heats the mixture.
(a)[2 marks]Describe the type of reaction taking place and explain what is meant by 'esterification'.
(b)[3 marks]Draw the displayed formula of the ester formed in this reaction.
(c)[1 mark]State one common use for this ester.
(d)[1 mark]Write the balanced chemical equation (using molecular formulae, not names) for the formation of the ester in part (b).