When the difference in boiling points of two liquids is very small,the separation is carried out by:

By the crystallisation of an impure compound,if the mother liquor becomes coloured,what shall be done to remove the colour?

In thin layer chromatography,a substance moved by a distance of $4 \ cm$,whereas the solvent moved by a distance of $5 \ cm$. Then the value of retardation factor $(R_f)$ is

If dichloromethane $(DCM)$ and water $(H_2O)$ are used for differential extraction,which one of the following statements is correct?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$:
Assertion $(A):$ $A$ simple distillation can be used to separate a mixture of propanol and propanone.
Reason $(R):$ Two liquids with a difference of more than $20^{\circ}C$ in their boiling points can be separated by simple distillation.
In the light of the above statements,choose the most appropriate answer from the options given below:

Identify the purification technique for the following mixtures:
$(i)$ Chloroform and aniline
$(ii)$ Impure acetone
$(iii)$ Impure aniline
$(iv)$ Chlorobenzene and bromobenzene