Reminder – Goggles must be worn at all times in the lab
You do not need to do a lab write-up for this lab. Your product (piece of fabric or T-Shirt
When several substances need to be separated from a mixture, the difference in the
polarity of molecules can be used to separate the different substances. This process is
called chromatography (writing in color). Often the different substances or fractions
separated out because they have different colors.
There are two phases in chromatography, the mobile phase, and the stationary phase.
The mobile phase consists of the mixture to be separated and a solvent whereas the
stationary phase consists of either a liquid or solid adhering to the surface the
chromatography is being preformed on. In this lab the fabric will be the stationary phase
and the solvent, ethanol and the ink will be in the mobile phase.
The different substances in the ink will travel at different rates because of their varying
polarity. Polar substances will be attracted by the polar solvent. The fastest moving
molecules will have the greatest attraction to the polar solvent and the slowest moving
molecules will have the strongest attraction to the stationary phase. As a result the
mixture will be separated.
To learn how the difference in polarity on substances can be used to separate mixtures.
1. Obtain a piece of fabric or get your white T-shirt that you brought with you to
school. If you brought a T-Shirt make sure that you write you name on the tag!
2. Under the fabric or inside the T-shirt place some wax paper to prevent to markers
from bleeding through.
3. With markers, color any design (school appropriate) that you would like. You will
get better results if your design does not have objects colored in. (Take no more
than 30 minutes to work on this step).
4. When you are completely done with your design take ethanol and using the pipet
attached to the co