What criterion is followed for the selection of the stationary phase in chromatography?

Glycerol boils at $290\,^{\circ}C$ with slight decomposition. Impure glycerine can be purified by

The purification method based on the following physical transformation is $:$
$\text{Solid} (X)$ $\xrightarrow{\text{Heat}} \text{Vapour} (X)$ $\xrightarrow{\text{Cool}} \text{Solid} (X)$

Identify the correct statements from the following:
$(i)$ Electromeric effect is a permanent effect.
$(ii)$ Hyperconjugation is a temporary effect.
$(iii)$ Fractional distillation is used to separate two liquids from a mixture if the difference in their boiling points is less.
$(iv)$ Different compounds are adsorbed on an adsorbent to different extents.

The principle of column chromatography is

State whether the following statements regarding fractional distillation are True or False:
$(i)$ The freezing of vapour of a liquid with a high boiling point takes place first.
$(ii)$ In the column,the more volatile liquid is present in a higher concentration in the vapour phase at higher levels.
$(iii)$ The condensed liquid flows down and provides heat to the vaporizing liquid.
$(iv)$ The liquid with the highest boiling point reaches the top of the column.