ch6 chromatography lab

Paper Chromatography and Polarity Name___________________ pd__

Background: Chromatography is a way to separate a mixture into the parts it is made of. In this activity, we will separate black and green inks into the colors that make them up. We will then use what has been learned about polarity to determine the most and least polar substance.

Procedure: Follow the directions given by the instructor for setting up the activity. Observe what happens as time goes on; when done make a sketch of the results. Use colors. Then answer the conclusion questions.

Results:

distance blue traveled _______ (bottom of color to middle of blue)

distance yellow traveled(bottom of color to middle of yellow) _______

distance red traveled(bottom of color to middle of red) = _____

distance solvent traveled _____ (bottom of color to top of water)

Conclusions:

1. These pens contain water soluble inks. What does that mean?

2. Do you think this would work with your pens? Why or why not? If not, is there a way to make it work with your pen? What?

3. What colors are in the green ink? In the black ink?

4. Which color travels the most? The least?

5. What carries the ink up the paper? Which color sticks the best to this substance?

6. Which color sticks the best to the paper? How can you tell?

7. Is water a polar or nonpolar molecule? Sketch a water molecule. Label its positive and negative ends if it is polar.draw another molecule, show how it sticks, label covalent and hydrogen bonds

8. From the demonstration with the marbles, which type of marble could represent water? Why?

9. From the demonstrations with the water, alcohol, and oil, you learned a general rule for predicting which things stick together, allowing mixing. What is that rule?

10. Give an example of 2 liquids that will mix and 2 that will not.

11. In this lab, what color do you think is the most polar? How can you tell from what you have seen?

12. Which color would be the hardest to wash out of your clothes? What is your reasoning?

13. Do some research (internet?), and find a way that chromatography is put to use.

14. ratio blue = db/dsolvent traveled= _____ ratio yellow = dy/ dsolvent traveled = _______ ratio red=____________