Practical: making and testing the smell of some esters in the lab
3 marks · EasyGive the names of the acid and alcohol used to make ethyl propanoate in the laboratory.
State one safety precaution you should take while mixing the reactants.
Describe how the ester can be separated from the reaction mixture after heating.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) Propanoic acid and ethanol
(b) Wear safety goggles / Use a fume cupboard / Avoid direct contact with acids
(c) Pour the mixture into sodium carbonate solution to separate the ester layer from the water
Common mistakes: Incorrectly naming the acid or alcohol; Suggesting to smell directly from the tube
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Names both propanoic acid and ethanol.
B2 (b) · 1 mark · Gives a valid safety precaution.
B3 (c) · 1 mark · Describes pouring into sodium carbonate solution to separate ester.
Worked solution
(a) Propanoic acid and ethanol are used.
(b) Wear goggles, use a fume cupboard, and avoid skin contact with the acids.
(c) Pour the cooled reaction mixture into sodium carbonate solution. The ester will float as a separate layer on the water.