Surfermondry
Posts: 1
Joined: Wed Jul 04, 2007 7:57 am

Rf factors

Postby Surfermondry » Mon Jul 09, 2007 5:32 pm

How will water, alchol, witchhazel, and hydrogen peroxiod absorb chromatography paper?

Louise
Former Expert
Posts: 921
Joined: Mon Jan 16, 2006 2:17 pm

Re: Rf factors

Postby Louise » Tue Jul 10, 2007 6:54 am

Surfermondry wrote:How will water, alchol, witchhazel, and hydrogen peroxiod absorb chromatography paper?


The rf factor is determined by the interaction between the paper and the solvent. The solvent polarity and vapor pressure are important, as are specific interactions like hydrogen bonds. The paper can have different thickness/roughness/and chemical composition. If you do chromatography in a closed container vs. open container, you can get the solvent front moving at different rates. Hydrogen peroxide is almost never used as a solvent, since it "chews up" most compounds through vigourous redox reactions. Most chemists just test these factors each time they run a chromatogram.
Louise


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