Honors Biology: Chromatography Lab Answer Key
Terms and Definitions (1 Point Each):
1. Chromatogram
2. Mobile Phase
3. Stationary Phase
4. Solute
5. Solvent
6. Heterogeneous Mixture
7. Homogenous Mixture
8. Endergonic Reaction
9. Exergonic Reaction
10. Heterotroph
11. Autotroph
12. Photosynthesis
13. Pigment
14. Adenosine Tri-phosphate
15. Absorption Spectrum
16. Cellular Respiration
17. Anaerobic Respiration
18. Aerobic Respiration
19. Fermentation
20. Lactic Acid Fermentation
21. Alcohol Fermentation
Analysis Questions (2 Points Each):
1. In procedure A (ink portion), what was the mobile phase and what was the stationary phase?
The target molecule is placed on chromatography paper is the stationary phase. The mobile phase is the solvent,
which in this case was denatured alcohol. The solvent rises up the paper, in other words the mobile phase
travels along the stationary phase. When it reaches the sample, the solvent carries the sample with it and
different components of the sample travel at different rates thus separating the sample into strips.
2. If you had an ink sample that did not separate into color bands during the procedure, what could be the
reason for this?
An ink sample that does not separate into bands of varying colors may be composed of a single pigment or
perhaps the target molecule was submerged in the solvent thus preventing the solvent from separating out the
sample’s pigments.
3. Why do some colors rise farther on the filter paper than others?
Several factors play a role in determining the distance that the colors rise depends on the size of the pigment
molecule; which pigments are more soluble in the denatured alcohol; and the level of attraction that the pigment
has to the chromatography paper.
4. What could it mean if pigments of the same color in ink samples from different pens have the same Rf
values?
