Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
91–100 of 133 · Hard
Question 91
7 marks · Hard
Answer and see the solution →Only some of the ethene reacts in the industrial hydration process for ethanol.
(a)[2 marks]Describe how unreacted ethene is dealt with in the hydration of ethene process.
(b)[2 marks]Explain how this affects the efficiency of ethanol production.
(c)[3 marks]Compare one disadvantage and one advantage of recycling unreacted ethene in this process to fermentation methods.
Question 92
2 marks · Hard
Answer and see the solution →A student writes the name 'proponoic acid' for a carboxylic acid with three carbon atoms in a straight chain.
State the correct IUPAC name for this acid. Give one reason for your answer.
Question 93
5 marks · Hard
Answer and see the solution →Vinegar is commonly used in food and cleaning products.
(a)[1 mark]Name the main carboxylic acid found in vinegar.
(b)[1 mark]State its molecular formula.
(c)[1 mark]Draw the displayed formula for this acid.
(d)[1 mark]Suggest one property of this carboxylic acid that makes it useful in cleaning products.
(e)[1 mark]Explain why this acid is classified as a carboxylic acid, referring to its structure.
Question 94
2 marks · Hard
Answer and see the solution →Draw the structural formula for butanoic acid and state the total number of hydrogen atoms in one molecule.
Question 95
2 marks · Hard
Answer and see the solution →Butanoic acid and hydrochloric acid have the same concentration. Explain why the pH of butanoic acid is higher than that of hydrochloric acid.
Question 96
5 marks · Hard
Answer and see the solution →A solution of ethanoic acid is reacted with calcium carbonate (CaCO₃) powder in a test-tube.
(a)[1 mark]State one observation you would make during the reaction.
(b)[2 marks]Write a balanced symbol equation for the reaction.
(c)[1 mark]Name the salt formed.
(d)[1 mark]Ethanoic acid reacts more slowly than hydrochloric acid of the same concentration. Explain why.
Question 97
2 marks · Hard
Answer and see the solution →Describe two ways you could show that propanoic acid is a weak acid.
Question 98
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 99
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 100
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.