Paper Chromatography Lab

Paper Chromatography Lab

(Separating Mixtures)

Doris Tapia

H-18

Chemistry

10-18-13

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

Pre-lab:

1.) What colors are mixtures?

-> Some of the colors that are mixtures are pink (white and red), purple (blue and red), green (blue and yellow), and etc.

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

 -> A substance that could be used to separate a mixture is water.

3.) What is Paper Chromatography?

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

•www.yesmag.bc.ca/projects/paper_chroma.html

Separating the Components of a Mixture

•Most laboratory work in biology and chemistry requires the use of techniques to separate the components of mixtures.

This is done by analyzing some property that distinguishes the components, such as their relative:

•size

•density

•solubility

•electrical charge

 

 

<= What is the set up for Paper Chromatography?

 

Hypothesis Questions:

1.) Are colors mixed to make other colors?
=> Yes, colors are mixed together to make other colors like purple is made from blue and red.

2.) Can mixed colors separate into their components colors?
=>Yes, they can.

3.) Can black separate into its component colors?

=> Yes, i do believe black can separated into its own colors. the colors i believe it can separated into is gray and brown.

Which colors will separate out?

Materials:

•Goggles

•Green and Black Markers

•Strips of Filter Papers

•Metric Ruler

•Plastic Cup

•Rubbing Alcohol

•Tape

•Pencil

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
(Name) sharpie  marker w/ alcohol	In the alcohol has not risen to the sharpie dot yet.	It still has not risen to the sharpie dot yet.	There was no separation made.
Black sharpie  with bleach	In the solution, bleach, it has risen but made to separation.	No separation has been made yet.	There was no separation made.
Black sharpie  w/ H2O	The water has risen completely and has made no separation for the black sharpie.	There has made no separation for the black sharpie.	There was no separation made.
Black sharpie with acetone	The acetone has risen completely and the black sharpie has started to spread.	It has completely spread the sharpie dot out revealing the colors black is made of.	It is revealing the colors black is made of.

 Data:

 Analysis and Conclusions:

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

Water	For this solution nothing really changed at all.
Bleach	For this solution nothing really changed at all.
Alcohol	For this solution nothing really changed at all.
Acetone	Acetone was the only solution that separated.

2.) What did the results indicate about the black ink? *What classification of matter could you give the ink?

=> I would say that this is not one of the best inks to separate.

3.) Is chromatography a useful separation method for ink mixtures? Explain based on your results. 
=> Yes, i do believe chomatography is a useful separation method because it separated what i needed to know. I also believe that you have to do the experiment right to get the result wanted.

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

=> If i could change something i would change the sharpie i would do a different color to show more the this method of separation works.

 Post Lab:

How does paper chromatography work? What do the results tell us? 
A: Preferential adsorption of chemical compounds (gases or liquids) in an ascending molecular-weight sequence.