H-18
Chemistry: Paper Chromatography
October 11, 2013
Paper Chromatography
Pre-Lab Objective: Create a process for separating a mixture. specifically an ink mixture.
Have you ever wondered if there was a way to separate color mixtures or even make ink move from paper? There is. Its called Paper Chromatography. Some colors that are mixtures are orange (red + yellow), pink (red + white), and purple ( blue + red). Chromatography is a method to separate complex mixture (like ink) into the chemicals that they are made from. Some substances that could be used to separate mixtures is water and alcohol.
The picture above is a picture of the setup of Paper Chromatography. The list below is a list of materials I used for my own Paper Chromatography lab.
Hypothesis
Colors are mixed to make other colors. An example of this is green ( blue + yellow). It is possible to separate mixed colors into their components. Black can separate into its components, just as green, purple and pink.
Materials:
-goggles
-black marker
-strips of filter paper
-ruler
-plastic cups
-rubbing alcohol
-tape
-pencil
-peroxide
-bleach
-Acetone and Ethyl
With every lab a person completes, there is a procedure they must follow in order to receive the most accurate results. Below is the procedure for Paper Chromatography.
Procedure:
1. Using the ruler, cut the filter paper into long, rectangular strips, about 3cm x 10cm.
*You need 2*
2. Measure 0.5cm 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 the dot touch the alcohol.*
4. Pour rubbing alcohol into a plastic cup to a depth of 1/2cm. Then rest the pencil on the rim of the cup so that the end of the pencil strips with the ink mark is just barely in contact with the alcohol.
5. Observe for about 8 minutes.
6.Let the strips dry by tapping it to a piece of paper provided. Put groups, names,
period, and ipod # on the sheet.
7. Repeat the process for the other solution for the same marker.
Tests in the Making:
Below are the four solvents used during this experiment.
Picture 1: Alcohol
Picture 2: Water
Picture 3: bleach
Picture 4: Acetone
Data:
Data Chart (Unable to upload Data Table/Chart )
Analysis and Conclusion:
Nothing really happened on the filter paper, with exception of alcohol and acetone.
Alcohol:By the time the strip was dry, only some of the ink faded.
Bleach: Nothing happened to any of the ink throughout the whole experiment.
Water: Once more, nothing happened to the ink. It stayed the same.
Acetone/Ethyl: The dot appeared the same. However, some of the ink dragged upward. The ink that dragged was faded.
The ink shown that the components of the ink have a larger size. The classification of matter is homogeneous mixture. Do to the fact that an ingredient in the black marker was ethyl, part of the fourth solvent. It explains why the dot was still intact. The only reason some of it dragged upward was mostly because of the acetone.
I believe that Chromatography does work to separate components of mixtures. With the black Expo marker as the mixture we were trying to separate into components, it became clear that only certain solvents can be used to separate certain mixtures. This is not to say that water or bleach cannot be used to separate other mixtures successfully, it just did not work for the Expo marker.
If I was allowed to change the experiment in any way, I would add more solvents. If we were to test the Expo marker with other different solvents, we possibly would have found other solvent that could have been successful.
Post Lab:
Paper Chromatography works by molecular-weight sequence, which means the different sizes of different components that are in the mixture.
I enjoyed completing this experiment because I have never done an experiment like this before. I like trying new experiments like these because it increases my knowledge in Chemistry. With this experiment, we were able to not only question Chromatography, but also test our beliefs on Chromatography.
