Write about column chromatography.

(N/A) Principle: The principle of column chromatography is based on the different adsorption capacities of the components of a mixture on an adsorbent.
Procedure:
$1$. In this method,a suitable adsorbent (e.g.,silica gel or alumina) is packed as a column in a long glass tube (similar to a burette) with a stopcock at the bottom.
$2$. $A$ plug of cotton or glass wool is placed at the bottom of the column to support the adsorbent. This acts as the stationary phase.
$3$. The mixture $(a+b+c)$ to be separated is dissolved in a suitable solvent and poured onto the top of the adsorbent column.
$4$. $A$ suitable solvent or mixture of solvents is then added continuously from the top,which is called elution.
$5$. The added solvent acts as the mobile phase,which moves down the column.
$6$. As the mobile phase moves,the components of the mixture are separated based on their differential adsorption. The component that is weakly adsorbed is eluted more rapidly than the component that is more strongly adsorbed.
$7$. The process of elution is repeated multiple times to achieve complete separation.
$8$. The different components are collected in separate conical flasks as different fractions.