Chromatography

Close All | Expand All

Edit   Delete - Last Modified By: rdu at 29/07/2014 11:32:56 AM

Have you ever written some work using pen and paper, or drawn a picture on paper with textas, then accidentally wet the paper?  Try doing this at home and see how the colours dissolve and "bleed" through the paper surface.  

This is a basic form of chromatography.  Chromatography is a technique of chemical analysis to separate chemicals (in this case, colours) in a solvent.  Water is the solvent in this example but different solvents can also be used.   

Edit   Delete - Last Modified By: rdu at 29/07/2014 11:37:16 AM

Google "paper chromatography" and have a look at the array of Images.   

Chromatography can be used in a variety of different forms of analysis.  Do some research and exploration about how chromatography is a useful tool. 

Edit   Delete - Last Modified By: rdu at 29/07/2014 11:40:28 AM

Chromatography separates substances by how strongly they adhere (or stick) to the medium (which is paper in this experiment).  The larger molecules bond more strongly to the paper, and the smaller molecules move with the solvent up the paper.  

This is an important concept to understand.  Watch the Khan Academy clip on the Basics of Chromatography below

Edit   Delete - Last Modified By: rdu at 29/07/2014 11:28:31 AM
Experiment: Separating Colours