Explain the following :
a) Column chromatography

Explanation

Column chromatography : In this type of chromatography the components of a mixture are separated by a column of adsorbent (stationary phase) packed in a glass tube. The column is fitted with a stopcock at its lower end. The mixture to be adsorbed on the adsorbent is placed at the top of the stationary phase. A suitable eluant (solvent) is allowed to flow down the column slowly. Depending on the degree to which the compounds are adsrobed, the components are separated. The most readily adsorbed substances are retained near the top and others come down accordingly to various distances.