Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Esters
68 practice questions
Topics covered
Practice questions
41–50 of 68
Question 41
2 marks · Easy
Answer and see the solution →Explain why the mixture of reactants is heated in a beaker of hot water rather than directly over a Bunsen burner when making esters in the laboratory.
Question 42
3 marks · Easy
Answer and see the solution →Table showing combinations and smells of esters made in a laboratory. Alcohol used Carboxylic acid used Ester formed Smell Ethanol Ethanoic acid Ethyl ethanoate Fruity, sweet Propan-1-ol Propanoic acid Propyl propanoate Banana-like Butanol Butanoic acid Butyl butanoate Pineapple (a)[1 mark]Which combination produces an ester that smells like pineapple?
(b)[1 mark]State the alcohol and carboxylic acid needed to make an ester with a banana-like smell.
(c)[1 mark]Suggest one reason why not much ester is formed during these short laboratory reactions.
Question 43
1 mark · Easy
Answer and see the solution →What is the correct method for smelling the ester produced in a laboratory preparation?
Question 44
3 marks · Easy
Answer and see the solution →A student is making propyl ethanoate in the laboratory.
(a)[1 mark]Write the names of the starting alcohol and carboxylic acid.
(b)[1 mark]Name the layer that will float on the water after adding sodium carbonate solution.
(c)[1 mark]State why the ester floats on water, but the alcohol and acid do not.
Question 45
2 marks · Easy
Answer and see the solution →A student follows the laboratory method to prepare an ester using 2 cm³ of ethanol (density = 0.79 g/cm³) and 2 cm³ of ethanoic acid (density = 1.05 g/cm³). Calculate the total mass of reactants (ethanol and ethanoic acid) used, in grams. Give your answer to 2 decimal places.
Question 46
2 marks · Easy
Answer and see the solution →During an esterification experiment, a student collects a layer of ester with a volume of 0.7 cm³. If the density of the ester is 0.91 g/cm³, calculate the mass of ester produced. Give your answer to 2 decimal places.
Question 47
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 48
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 49
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 50
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