Question

what would you observe if you used a ballpoint pen instead of a pencil to mark the chromatography paper?

Answer 1

Answer:

It basically messes up the results

Explanation:

Pen ink consists of resins, pigments and other colouring dyes dissolved in appropriate solvents like propylene glycol, propyl alcohol and some other ethers. If the ball point pen is used to mark on the chromatography paper then these pigments will also move along with the solvent and interfere with the spots of our analyte.

If you use a ball point pen when doing a chromatogram, then the ink would separate as it is a mixture and run down the paper.

Graphite, or pencil lead however, is not an organic material and therefore will not be affected by common organic solvents used for thin-layer chromatography. Pen ink on the other hand will be readily absorbed by the solvent and will move up the plate.