3.9 Separation & Chromatography

01Separating by attraction

Chromatography separates components by how strongly they cling to the stationary phase vs. dissolve in the mobile phase. Components that like the mobile phase travel farther.

Distillation separates by boiling point (IMF strength).

02Notebook box

Rf = distance of spot / distance of solvent front. Polar paper + nonpolar solvent → nonpolar compounds travel farther.

Worked example: Spot 2.4 cm, solvent 6.0 cm → Rf = 0.40.

Key takeaways

✦Like attracts like.
✦High Rf = more attracted to mobile phase.
✦Distillation uses boiling point.

Quick check

Did it stick?

1.Polar stationary phase: which travels farthest?

2.Spot 3 cm, front 5 cm. Rf?

3.Distillation separates by…