I need help with this paper chromatography lab. In the column that says splitting and Rf values if the ink split into multiple colors do I put

I need help with this paper chromatography lab. In the column that says splitting and Rf values if the ink split into multiple colors do I put multiple numbers down? Does the answer need to be in inches or centimeters) Is the Starting Spot where the ink has moved to? I don't get it. I did not use coffee filters because they grabbed the liquid and submerged the filters. Any help is appreciated. Thank you.

Materials: 8" Aluminup pie plate(or similar wide shallow pan), Toothpicks, Food coloring, Large Coffee Filters, Pencil, Rubbing alcohol (70% Isopropyl Alcohol), several Ink pens, Measuring Cup, Ruler

Procedure:

1. Using the ruler measure about 1 cm from the edge of the coffee filter. Mark eight evenly spaced lines around the filter with the pencil, each one should be about 1 cm from the edge of the coffee filter. Be sure NOT to use ink to mark these eight lines. These are the starting lines for each of your eight samples.

2. Use a toothpick to spot the four food coloring dyes on four of the eight starting lines pencil marks. Allow each spot to dry then re-spot with the same color two or three more times. This should give you a good dark starting spot for each of the four food colors.

3. At the other four starting spots mark spots using four different ink pens.

4. Mark the top of each starting spot (4 food color and 4 pens) with your pencil and below each starting spot indicate the color and type of spot. For example you could label FG for food color - green or PR for pen - red, etc.

5. Take the coffee filter with the spots and fold it so the edges below all eight spots is sitting in the pie pan. Only the edges should be touching the pie pan. The rest of the coffee filter should be up above the pan.

6. Add rubbing alcohol to the pie pan to just below the spots. Make sure you do NOT have the liquid in the pan as high as any of the eight spots.

7. You should now see the liquid begin to move up the coffee filters (wick up the filter paper). Continue to let the liquid move up the coffee filter until it gets near the top of the filter. During this process you should also notice the spots of color moving up the filter paper and some of them splitting into multiple colors. Do NOT let the liquid move all the way to the top of the coffee filter.

8. When the coffee filter appear to be wet almost to the top of the filter remove it from the pie pan and draw a pencil line all along the top showing the highest point the liquid reached all across the coffee filter. Draw a pencil line at the top of each color for each spot. If a spot split into multiple colors be sure to draw a line for each color that separated.

9. Let the filter paper dry.

10. For each starting spot you will need to measure how far the liquid moved up the paper and how far each color spot moved. If a starting spot split into multiple colors you will need to measure how far each color spot moved.

How far the liquid moved: Measure from the line you drew at the top of your starting spot to the line you drew at the maximum distance the liquid moved up the paper.

How far each spot moved: Measure from the line you drew at the top of your starting spot to the top of the color spot. (Repeat for each color that came from that starting spot.)

11. Calculate the ratio of how far each color spot moved divided by how far the liquid moved for each starting spot. This ratio is called the Rf value. (distance spot moved)/(distance liquid moved) = Rf Report an Rf value for each of the spots.

12. Repeat these procedures 1 - 11 using a different liquid. Instead of all rubbing alcohol use a mixture of equal amounts of water and rubbing alcohol. (1/4 cup alcohol and 1/4 cup water mixed)

13. Note differences in the movement AND splitting of the different starting spots compared to the first procedure.

14. Report Rf values for each of the spots.

15. Repeat these procedures 1 - 11 using a different liquid. Instead of all rubbing alcohol use water. (NOTE: Water tends to move up the filter paper rapidly and may continue to move up briefly after the coffee filter is removed from the pan.)

16. Note differences in the movement AND splitting of the different starting spots compared to the first two procedures.

17. Report Rf values for each of the spots.

18. Using the Report page at the end of these instructions to lists the eight starting spots you generated for each of the three procedures, clearly indicating what ink or food coloring you used for each spot. List for each of the starting spots the splitting and Rf values for each of the final spots on your chromatograms that came from that starting spot.

Give a summary statement of the similarities and differences you saw in the three different procedures with the three different liquids used.

Answer the following questions.

1. Which starting spot(s) seem to only contain one pigment (did not split on any of the chromatograms)?

2. Which starting spot seemed to contain the most pigments (showed the most different final spots)?

3. Which solvent (liquid) seemed to be the best at separating pigments in the inks?

19. Take a picture of each of your three chromatographs and imbed them in your report or attach them as separate files when you submit the report.

20. BE SURE to include your name and course section and number in the Word file.

Submit your Word file in Blackboard using the submission link for this lab assignment.

Paper Chromatography (this is what get submitted)

REPORT SHEET

Alcohol Trial

STARTING Splitting and Rf Values for

SPOT Final Spot(s)

1) ____________ ________________________________________________________

2) ____________ ________________________________________________________

3) ____________ ________________________________________________________

4) ____________ ________________________________________________________

5) ____________ ________________________________________________________

6) ____________ ________________________________________________________

7) ____________ ________________________________________________________

8) ____________ ________________________________________________________

Alcohol/Water mixture Trial