Using the provided information in the following paper chromatogram,calculate the $R_{f}$ value of $A$ .......... $\times 10^{-1}$.

Which of the following compounds can be separated by the steam distillation method?

Which purification method is used to separate liquids that have a sufficient difference in their boiling points?

Given below are two statements:
Statement $I$: Vapours of the liquid with higher boiling point condense before vapours of the liquid with lower boiling points in fractional distillation.
Statement $II$: The vapours rising up in the fractionating column become richer in high boiling component of the mixture.

The most suitable method of separation of a $1:1$ mixture of $ortho$- and $para$-nitrophenols is:

Benzoic acid is an organic compound. Its crude sample can be purified by crystallisation from hot water. What characteristic differences in the properties of benzoic acid and the impurity make this process of purification suitable?