The principle of column chromatography is

Give a brief description of the principles of the following techniques taking an example in each case.
$(a)$ Crystallisation
$(b)$ Distillation
$(c)$ Chromatography

What is adsorption chromatography? Write its types.

What is an eluant?

Which technique is used for the separation of a compound present in an aqueous solution?

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.