Chemistry 5070 · O Level · Separation and purification
Separation and purification — practice question
Using the apparatus shown, a student separates propanoic acid (b.p. $141\,^{\circ}\text{C}$) from butanoic acid (b.p. $164\,^{\circ}\text{C}$).
(a)[1]
Explain why the receiver flask has to be left open.
(b(i))[1]
What temperature is shown on the thermometer when the first drops of liquid reach the receiver flask?
(b(ii))[1]
What is the name of this liquid?
(b(iii))[1]
How can the student tell that all of this liquid has passed over?
(c)[1]
Suggest a safety item that the student should wear for this experiment.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “To stop pressure building up / to prevent explosion / to stop pressure increasing” …