Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Carboxylic Acids
48 practice questions
Topics covered
Practice questions
41–48 of 48
Question 41
5 marks · Easy
Answer and see the solution →Propanoic acid is a member of the carboxylic acid family.
(a)[1 mark]Draw the displayed formula of propanoic acid.
(b)[2 marks]State why propanoic acid is described as a weak acid.
(c)[2 marks]A piece of magnesium ribbon is added to propanoic acid. What do you expect to observe? Explain your answer.
Question 42
6 marks · Normal
Answer and see the solution →A student is learning about carboxylic acids and how they react with metals.
(a)[1 mark]State the name of the unbranched-chain carboxylic acid with two carbon atoms.
(b)[1 mark]Write the molecular formula for the acid you named in (a).
(c)[2 marks]When this acid reacts with zinc metal, a salt and hydrogen gas are produced.
i. Write a balanced chemical equation (using molecular formulae) for the reaction between the acid from (a) and zinc metal.
(d)[1 mark]Name the salt formed in the reaction in part (c).
(e)[1 mark]Give one observation you would expect when this reaction takes place.
Question 43
6 marks · Normal
Answer and see the solution →A bottle of vinegar is labelled as containing ethanoic acid.
(a)[1 mark]State the name of the main acid found in vinegar.
(b)[2 marks]Explain what is meant by the term 'weak acid', using ethanoic acid as an example.
(c)[2 marks]Vinegar reacts with magnesium metal. Describe the reaction and give one reason why the reaction is slower compared to dilute hydrochloric acid.
(d)[1 mark]State one observation you would make when magnesium reacts with vinegar.
Question 44
6 marks · Normal
Answer and see the solution →A student wants to prepare a sample of sodium butanoate by reacting sodium metal with butanoic acid.
(a)[2 marks]Draw the displayed formula for butanoic acid.
(b)[2 marks]Write a balanced symbol equation (using molecular formulae) for the reaction between sodium metal and butanoic acid.
(c)[2 marks]Calculate the mass of sodium metal required to react completely with 0.10 mol of butanoic acid. (Relative atomic mass: Na = 23)
Question 45
6 marks · Normal
Answer and see the solution →Study the information about the carboxylic acid family and their behaviour as acids.
(a)[2 marks]Give the name and molecular formula of the unbranched-chain carboxylic acid with three carbon atoms.
(b)[2 marks]Explain why carboxylic acids, such as the one named in (a), are described as weak acids.
(c)[2 marks]A student adds magnesium strip to a solution of this acid. The reaction is much slower than when magnesium is added to dilute sulfuric acid. Explain two reasons for this difference.
Question 46
7 marks · Hard
Answer and see the solution →A student is investigating the behaviour of ethanoic acid with different substances in the laboratory.
(a)[1 mark]State the main component of vinegar.
(b)[1 mark]Give one observation when magnesium metal is added to ethanoic acid.
(c)[2 marks]Write a balanced chemical equation for the reaction of ethanoic acid with magnesium.
(d)[2 marks]Explain why ethanoic acid reacts more slowly with magnesium than hydrochloric acid.
(e)[1 mark]Name the salt formed in the reaction between ethanoic acid and magnesium.
Question 47
7 marks · Hard
Answer and see the solution →This question is about carboxylic acids and their properties.
(a)[2 marks]Draw the displayed formula of propanoic acid.
(b)[1 mark]State how many carbon atoms are present in a molecule of propanoic acid.
(c)[2 marks]Describe what is meant by a weak acid. Use propanoic acid as an example in your answer.
(d)[2 marks]Propanoic acid reacts with sodium metal. Write a word equation for this reaction.
Question 48
7 marks · Hard
Answer and see the solution →Answer the following about unbranched-chain carboxylic acids and their reactions.
(a)[2 marks]Give the name and molecular formula of the unbranched-chain carboxylic acid with one carbon atom.
(b)[1 mark]Carboxylic acids react with magnesium carbonate. State one observation you would make during this reaction.
(c)[2 marks]Write a balanced chemical equation (using molecular formulae) for the reaction between ethanoic acid and magnesium carbonate.
(d)[2 marks]Using your knowledge of acid reactions, explain why the reaction between ethanoic acid and magnesium carbonate is slower than the reaction between hydrochloric acid and magnesium carbonate.