Illustrated Guide to Home Chemistry Experiments

Chapter 6 Laboratory: Separating Mixtures 111

is just emerging from the spot, showing that, although it is
at least somewhat soluble in acetone, it binds to the acetone
solvent and the paper substrate about equally. The fourth strip
was also spotted with green food coloring dye, but uses water,
which is extremely polar, as the solvent. Both the blue and yellow
components of the dye bind tightly to water, and were therefore
carried far up the strip. Note that some separation is evident, with
the blue component concentrated toward the top of the solvent
front and the yellow component lagging slightly.

Finally, the fifth strip was spotted with a mixture of green and

red food coloring dye, and developed using acetone. Clearly, the

red component of the mixed dyes bonds very tightly to acetone,

and is concentrated and relatively sharply delineated near the

solvent front. The blue component lags somewhat, and is more

spread out. As was true with the third strip, the yellow component

has barely made any progress, and is visible as a brownish area

near the starting point, where the yellow dye is mixed with some

remaining red and blue dye.

TABLE 6-5: Basic chromatography—observed data

StripAnalyte SolventSolvent front notes

ExampleBrown permanent penAcetone9.15 cm Red component at 3.80 cm (Rf 0.42); green at 6.75 cm (Rf 0.74)

A.

B.

C.

d.

E.

f.

G.

H.

I.

j.

k.

L.