$(a)$ Give uses of chromatography.
$(b)$ Give the meaning of the word chromatography.
$(c)$ Write the first use of chromatography.

(N/A) The uses of the chromatography technique are as follows:
$(i)$ In the purification of compounds.
$(ii)$ To test the purity of compounds.
$(iii)$ To separate mixtures into their individual components.
$(b)$ The name chromatography is derived from the Greek word $chroma$,meaning $color$. It was named chromatography because it was initially used to separate colored substances.
$(c)$ Chromatography was first used for the separation of colored substances found in plants. The procedure is as follows:
$(i)$ The mixture of colored substances obtained from the plant is applied onto a stationary phase,which may be a solid or a liquid.
$(ii)$ $A$ pure solvent,a mixture of solvents,or a gas is allowed to move slowly over the stationary phase.
$(iii)$ The components of the adsorbate mixture get gradually separated from one another.
$(iv)$ The phase moving over the stationary phase (liquid or gas) is called the mobile phase.