Problem Set 3R-1B:
Won't the second molecule, which has more carbon atoms,
move more slowly in paper chromatography than the first
molecule therefore have a smaller Rf? I think mobility
depends on size.
Size is not a factor in paper chromatography. The distance between
cellulose fibers is huge compared to the molecules.
Paper chromatography: Rf value is defined as distance to the
edge of the paper (No), but the ratio of...what? So that a LARGE Rf value
signifies that the aa is hydrophilic? Or phobic?
Rf is the ratio of the distance moved by your favorite compound to the
distance moved by the liquid front at the time the experiment is stopped. A
large Rf would be characteristic of a more hydrophobic compound, since
hydrophobic compounds will be more soluble in the more mobile, non-polar
solvent, and so will travel farther than hydrophilic compound. which spend
more time in the stationary, polar solvent.