Chromatography Techniques:

Question 1

Chromatography

Answer 1

Chromatography is used to separate and analyse small amounts of mixtures and to determine the composition and purity of substances.

Question 2

Methods of Chromatography

Answer 2

Methods involve altering a stationary phase and a mobile phase to separate components based on:
Different types of polar groups (type and strength of intermolecular forces).

The amount of charged and polar chemical groups,
Its molecular weight,
Its geometry,
The position and numbers of carbons-carbon double bonds.

Stationary phase (fixed): is a solid or liquid on which components can bonds/interact/adsorb to. When components interact with the stationary phase, it slows their motion

Mobile phase: A liquid or a gas that passes (or moves) over or through the stationary phase. It dissolves and carries the components of the mixture with it.

Question 3

Paper Chromatography

Answer 3

Stationary Phase: chromatography paper

Mobile Phase: suitable solvent (water, ethanol or other organic solvent)

Separation: As the solvent moves up the paper it dissolves the components and moves them up the paper. The more soluble a component is, the further it moves.

Question 4

Advantages of Paper Chromatography and Thin Layer

Answer 4

Paper Chromatography:
1. Cheap
2.Little preparation
3.More efficient for polar and water-soluble compounds
4. Easy to handle and store
Thin Layer Chromatography:
1. Detects smaller amounts
2.Better separation of less polar substances
3.A wide range of stationary phases available
4.Corrosive materials can be used