http://siggy.chem.ucla.edu/VOH/136/TLC.pdf
The above site explains a little about why some analytes move fast and some slow.
Check my thinking on these.
a. Aren't the Hs at the double bond slightly acidic? But I would expect 1-4 dimethylbenzene to be less polar. The fact that the Rf factor was so high means that the solvent used was much more polar than either of the components. I would try a different mobile phase; i.e., one less polar.
b. The Rf value of only 0.05 means the components hardly moved at all; i.e., they were strongly attracted to the TLC plate surface. Hexane is a non-polar solvent; the solution is to use a more polar solvent.
c. When the solvent moves up past the top of the plate it means you let it develop too long.
Consider the following errors that could be made when running TLC. Indicate what should be done to correct the error.
a) a two-component mixture containing 1-octene and 1,4-dimethylbenzene gave only one spot with an Rf value of .95. The solvent uses was acetone.
b) a two-component mixture containing a dicarboxylic acid and tricarboxylic acid gave only one spot with an Rf value of .05. The solvent used was hexane.
c) when a TLC plate was developed, the solvent front ran off the top of the plate.
thanks in advance for all the help... i have been stuck on this question for a while!
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