Separation of Solutions and Mixtures Chromatography

Separation of Components (Solutions)

Components of a solution cannot be separated by filtration, but can be separated using processes that take advantage of differences in the intermolecular interactions of the components.

Chromatography

A separation technique that separates chemical species by taking advantage of the differential strength of intermolecular interactions between and among the components of the solution (mobile phase) and with the surface components of the stationary phase.

Stationary Phase (Chromatography)

The solid or thick liquid material (e.g., paper, silica, alumina) on which the separation takes place; has a specific polarity.

Mobile Phase (Chromatography)

The solvent (liquid or gas) that moves through the stationary phase; carries the components of the mixture.

Separation in Chromatography

Components separate because they have different affinities for the stationary phase and the mobile phase (difference in IMF strengths).

Polarity and Travel Distance (Chromatography)

More similar in polarity to the mobile phase, the farther a component will travel; more polar components travel shorter distances on polar stationary phases.

Rf (Retention Factor)

A retention factor unique per solute/dye defined by the ratio of the distance the dye traveled to the distance the solvent traveled (Rf = ddye/dsolvent).###
Paper Chromatography

Thin Layer Chromatography (TLC)

A type of chromatography where the stationary phase is typically silica or alumina on a sheet of plastic.

Column Chromatography

A type of chromatography where the stationary phase (e.g., silica or alumina) is packed into a vertical column.

Distillation

A separation method that physically separates mixtures based on the difference in boiling points and intermolecular forces; vapor pressure effects are utili