2. (responsible for the phenomenon of capillary action)
“...drawing of molecular interactions associated with macroscopic observations”
hydroxyl group
hydrogen bonding
Surface of SiO2
Attraction of water molecules to hydroxyl groups on the surface of SiO2 (glass)
(responsible for the phenomenon of capillary action)

3. Cellulose The main component of cotton and other plant fibers
A polysaccharide with the general formula (C6H10O5)n
It has been estimated that half of all organic carbon is tied up in cellulose.

4. Water molecules in the air, as well as those still present from the paper production process, attach to the hydroxyl groups…
…and makes a very thin layer of water molecules on the surface of the cellulose.

5. potassium bitartrate (cream of tartar)
sodium bicarbonate
cornstarch polymer

6. Chromatography: Used to separate mixtures into their components.
Important Terms:
Stationary Phase: the paper (when doing paper chromatography)
Mobile Phase: the solvent
Rf value (AKA the retention or retardation factor): ratio of the distance traveled by the molecule(s) in the mixture being separated and the distance traveled by the solvent

7. Molecules in the mixture you are asked to separate.
Blue 1
Molecules in the mixture you are asked to separate.
Red 40
Yellow 5

8. Student Responsibilities:
Prelab Guiding Questions – Part I and II (the computer simulation is optional)
HW for tonight, collected on Monday.
Not necessarily typed – Don’t be verbose.
The Lab Report
Hypothesis Statement – Which of the five solvents do you consider the best and why?
1 or 2 sentences and typed [along with the rest of the report.]
Experimental Design – Step by step procedure as simple bullet points. Must test all solvents not just two. (Clear enough so that someone else could repeat the experiment and get the same results…developed in class.)
Data and Calculations Table – Measured and calculated values to allow you to assess your hypothesis. Staple chromatograms to space near table…split amongst partners.

9. Student Responsibilities (cont’d):
Data Collection and Computation
Question 1B
Question 2A and B
Question 4A and B (only important portions of molecules need be shown)
Question 5A and B (find the “supplementary info” link on the webpage given on p Use the “environmental impact” [green] column.)
Question 6
Question 7 (just one sample calculation with all values reported in the data table.)
Argumentation and Documentation
No more than 5 sentences
Be sure to cite specific evidence from the experiment to support your explanation