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

Match List-$I$ with List-$II$.

List-$I$ (Purification technique)	List-$II$ (Used to separate)
$A$. Simple distillation	$I$. Steam volatile compound
$B$. Fractional distillation	$II$. Two liquids with large difference in boiling points
$C$. Steam distillation	$III$. Liquid decomposing at its boiling point
$D$. Distillation under reduced pressure	$IV$. Two liquids with close boiling points

Thin-layer chromatography is an example of

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

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.

Which of the following compounds is used as an adsorbent in column chromatography?