Which one of the following can be purified by sublimation?

Fill in the blanks:
$1$. In differential extraction from two layers,the .......... layer is above because .............
$2$. The organic solvent used in differential extraction is .......... in water.
$3$. If an organic compound is ......... soluble in an organic solvent,then the continuous extraction technique is used.
$4$. ........ solution is added to produce the precipitate of halide for the estimation of halogen.

The principle of column chromatography is

Match List-$I$ with List-$II$:

List-$I$ (Technique)	List-$II$ (Application)
$A$. Distillation	$I$. Chloroform-Aniline
$B$. Fractional distillation	$II$. Separation of crude oil fractions
$C$. Steam distillation	$III$. Aniline-Water mixture
$D$. Distillation under reduced pressure	$IV$. Separation of glycerol from spent-lye

Choose the correct answer from the options given below:

Chromatography is used for the purification of which of the following?

Chromatography is a valuable method for the separation,isolation,purification,and identification of the constituents of a mixture. It is based on the general principle of: