Return to site

IB Chemistry Unit 1 Module 3 Analysis Revision I

Chromatography

October 14, 2022

Basics of chromatography

In IB chemistry curriculum, chromatography is a technique used to separate components in a mixture and identify them by comparing their Rf/retention time value to a database.

Mobile phase – the phase that moves : liquid or gas
Stationary phase – the phase that doesn’t move : solid or liquid

Chromatography works on the basis that different components have different affinities for a stationary and mobile phase. The greater the interaction the component has with the stationary phase the more it is slowed down; the difference in speeds is what creates the separation.

Methods of separation in IB chmeistry:
•    Adsorption : solid or liquid stationary phase
•    Relative solubility : liquid or gas stationary phase

In IB chemistry, adsorption – the process by which a solid holds molecules of a gas or liquid or solute as a thin film on the surface of a solid or, more rarely, a liquid.

End of this part! Please read part II !

Drafted by Gina (Chemistry)