Deja Vasquez

H-23

Date Started: October 11, 2013

Paper Chromatography

Pre-Lab: 

• Lab Objective: Create a process for separating a mixture, specifying an ink mixture.

1. What colors are mixtures? 

- Orange (yellow and red), Green (blue and yellow), Purple (red and blue), Pink (white and red), Black (...grey)

   
2 . What substances could be used to separate a mixture? 

- Alcohol, Water, Vinegar, hydrogen peroxide, etc. 

3. What is Paper Chromatography? 

- Chromatography is a method for analyzing complex mixtures (ink) by separating them into the chemicals from which they are made.

The Set-Up: 

Water                                                                         Alcohol

Questions/Hypothesis:

1. Are colors mixed to make other colors? 

  - Yes, that's how we get so many colors.

2 . Can mixed colors separate into their component colors? 

  - Yes, the same way they can be mixed together.

3. Can black separate into a component color? 

  - It should be able to.

4. Which colors will separate out? 

  -I think a whole bunch of  dark colors make black.

Materials: 

Black Sharpie Marker
Metric Ruler
Goggles
Plastic Cup
Rubbing Alcohol 
Tape
Pencil
Strips of Filter Papers
Water

Procedure: 

1.Using the ruler, cut the filter paper into long, rectangular strips, about 3 cm x 10cm. *You need 2*

2.Measure 0.5 cm from the bottom of the paper strip and draw a horizontal line with your pencil across the width of the strip. Then, use the black marker to make a dot on the pencil line.

3.Tape the paper strip around the pencil so that the very bottom of the strip touches the alcohol.**Do not let ink dot touch alcohol

4. Pour rubbing alcohol into a plastic cup to a depth of ½ cm. Then, rest the pencil on the rim of the cup so that the end of the pencil strip with the ink mark is just barely in contact with the alcohol.

5. Observe for about 8 minutes.

6. Let the strip dry by taping it to a piece of paper provided.  Put group names, period, and Ipod # on the sheet.

7. Repeat the process for the other solution for the same marker. 

Data Table: 

Observations	Observation at 3 minutes	Observation at 6 minutes	Dry test strips
Sharpie black marker w/ alcohol	Indigo	Indigo	Indigo and Grey
Sharpie black marker w/ H2O	Black	Black	Black
Test strips after they are dry	Indigo and grey w/ alcohol Black w/ H2O	Indigo and grey w/ alcohol Black w/ H2O	Indigo and grey w/ alcohol Black w/ H2O

Water at 6 minutes                   Alcohol at 6 minutes                  Dry Test Strips

Analysis and Conclusion:

1. What is appeared on the filter paper? Describe all results.

- In the alcohol results what had appeared was the water rose up the strip and created a smudge of indigo, and grey. In the water results nothing occurred while the water rise and dried.

2. What did the results indicate about the black ink? What classification could you give the ink?

- The results indicated that there are colors that are mixed to make black ink. The classification I would give the ink is a liquid. 

3. Is chromatography a useful separation method for ink mixtures? Explain based on your results.

- I believe that chromatography is a useful separation method because I had no idea what color would come out of black ink and with this method I learned that Indigo comes out. 

4. If you could alter the experiment to test another condition or factor, what would you change or test?

- If I could alter the experiment to test another condition I would try a non-colored nail polish because I believe I would get better results than the water. Nail polish is pretty strong like the alcohol and I know I would get a better outcome. 

Post Lab Questions: 

How does Paper Chromatography work? What do the results tell us?

-Preferential adsorption of chemical compounds (gases or liquids) in an ascending molecular-weight sequence.