The molar composition of the vapor in equilibrium with a boiling liquid that has a composition of 60% A and 40% B is a vapor with a composition of 40% A and 60% B.
The composition of the boiling liquid that produced this vapor is 50% A and 50% B.


Approximately one-hundred and ten degrees Celsius.

For a microscale distillation apparatus using a Hickman head, the bulb should be located just below the Hickman head, such that the ‘curve’ before the bulb is about parallel with it.
For a macroscale distillation apparatus using a distilling head, the bulb should be located just below the below the sidearm of the distilling head.  The entire bulb must be immersed in the vapor to achieve an accurate reading.

A good separation can be achieved with a simple distillation under the condition that the boiling point difference between the two compounds is greater than one-hundred degrees Celsius, within reason.  A good separation can also be achieved if the difference in concentrations of the two compounds is greater than a 9:1 ratio.