Chemistry 5070 · O Level · Separation and purification
Separation and purification — practice question
A student uses the apparatus shown to separate hexane, $\text{C}_6\text{H}_{14}$, (b.p. $69^{\circ}\text{C}$) from heptane, $\text{C}_7\text{H}_{16}$, (b.p. $98^{\circ}\text{C}$).
(a)[2]
Identify two mistakes in the apparatus used by the student.
(b(i))[1]
Name apparatus A in the diagram.
(b(ii))[1]
What is apparatus A used for?
(b(iii))[1]
Name apparatus B in the diagram.
(b(iv))[1]
What is apparatus B used for?
(c(i))[1]
What is the thermometer reading when the first few drops of liquid appear, in C?
(c(ii))[1]
Name the liquid shown.
(d)[2]
Suggest a suitable method for heating the mixture and explain why you chose it.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Thermometer/bulb too low / should be higher / must not touch beads / should be at entrance to condenser” …