Two liquids $(A)$ and $(B)$ can be separated by the method of fractional distillation. The boiling point of liquid $(A)$ is less than the boiling point of liquid $(B)$. Which of the liquids do you expect to come out first in the distillate? Explain.

(A) The liquid $(A)$ with the lower boiling point comes out first in the distillate.
Fractional distillation is used to separate the components of a mixture if their boiling points differ by $20^{\circ}C$ or less. In this method,a fractionating column is used between the flask and the condenser. The purpose of the fractionating column is to provide hurdles for the ascending vapours and to provide a large surface area for condensing the high-boiling liquid.
As a result,the vapours of the low-boiling liquid $(A)$ will move up,while those of the high-boiling liquid $(B)$ will condense and flow back into the flask.
Therefore,in this method,liquid $(A)$ with the lower boiling point will distil first,and liquid $(B)$ with the higher boiling point will distil afterwards.