Question

elect all statements below that apply to Column Chromatography.

		Column chromatography can be used to purify small (< 0.1 g) sample mixtures.
		The compound in a mixture with the lowest Rf value will exit the column first.
		Column chromatography is often used to purify large (10 g) sample mixtures.
		Column chromatography is used mainly as an analytical tool.

Answer 1

Column chromatography may be defined as a separation process involving the percolation of a liquid solute through a column packed with finely divided material.

In this tecnique the stationary phase is a solid (alumina or silica gel) which is packed in a column and the moving phase is a solvent (benzene or ether ) contaning the mixtuers to be separated. stationary pase is fixed in place for the chromatographic procedure.

The more polar sample of lowest Rf value retained on the stationary phase longer. Thus the least polar compound will elute from the column first, followed by each compound is of increasing polarity.

Rf value =distance travelled by the component/ distance travelled by the solvent

Rf defines the movement of the substances relative to the solvent front in a given chromatographic system.

column chromatography is a method to purify chemical compounds from mixtures of compunds. It is used for micrograms to kilograms means large (10 g ) sample & small(<0.1 g ) sample mixtures.

It is used mainly as an analytical tool for purification and separation.

All statements are correct to the column chromatography.