Chromatography - Chemical Separation of Colors
Vickie Townsend Crown Fine Arts Academy
2128 S. St Louis
Chicago IL 60623
(312)534-1680
Objective:
1. After the lesson and participation in activity, the third grade students
will be able to use the scientific method of problem, hypothesis, materials,
results and conclusion to solve the following problem:
What color or colors are red, yellow, blue, green, purple, orange, brown
and black made from?
2. The students will explore, observe, and examine colors and events using a
combination of senses to collect and process data.
3. The students will suggest possible reasons as to why and how events have
taken place.
4. The students will follow directions and procedures in the science
laboratory.
Materials:
This is a list of materials for a class of 16 students in groups of four.
8 beakers filled 1/8 with water (2 beakers per group)
8 packs of Sanford markers (2 packs per group)
128 2" by 6" filter papers (32 per group)
16 Chromatography Results Sheets (4 per group)
Strategies:
The teacher will write the word chromatography on the board and explain
that chromatography is the separation of ink colors by allowing a solvent to
seep up filter paper so that the ink dissolves and separates, often in many
colored layers.
The teacher will explain that chemists use chromatography to separate the
chemicals in a mixture then each chemical can be analyzed. The teacher will
explain that medical chemist use chromatography to find drugs in a person's
blood. The teacher will explain that environmental chemist use chromatography
to find pollutants in water and other substances.
The students will take a red marker and make a line going across the paper
1/4 of the way from the bottom of the filter paper. They will dip the filter
paper in the beaker with the water in it. They will let the filter paper absorb
the water and notice changes in color. They will repeat the above procedure for
the colors yellow, blue, purple, orange, brown and black. They will complete
the Chromatography Results sheet and the Conclusion section of this worksheet.
The students will discover which colors are the primary colors. These
are the colors that will not show a change in color when the filter paper
absorbs the water. They will also discover that the water goes up the paper
towel. This happens because paper towels have holes which pull the water up.
This is called the capillary reaction.
Conclusion:
Red is made up of the color or colors ________________________________.
Yellow is made up of the color or colors ________________________________.
Blue is made up of the color or colors ________________________________.
Green is made up of the color or colors ________________________________.
Purple is made up of the color or colors ________________________________.
Orange is made up of the color or colors ________________________________.
Brown is made up of the color or colors ________________________________.
Black is made up of the color or colors ________________________________.
Performance Assessments:
The students must correctly complete the Chromatography Results sheet and
the Conclusion section of this sheet with 80% accuracy.
CHROMATOGRAPHY
RESULTS
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w w
Red w w
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w w
Yellow w w
affffffffffq
`ffffffffffp
w w
Blue w w
affffffffffq
`ffffffffffp `ffffffffffp
w w w w
Green w w w w
affffffffffq affffffffffq
`ffffffffffp `ffffffffffp
w w w w
Purple w w w w
affffffffffq affffffffffq
`ffffffffffp `ffffffffffp
w w w w
Orange w w w w
affffffffffq affffffffffq
`ffffffffffp `ffffffffffp `ffffffffffp
w w w w w w
Brown w w w w w w
affffffffffq affffffffffq affffffffffq
`ffffffffffp `ffffffffffp `ffffffffffp `ffffffffffp
w w w w w w w w
Black w w w w w w w w
affffffffffq affffffffffq affffffffffq affffffffffq
SCITECH
18 West Benton
Aurora IL 60506
(708) 859-3434
CHROMATOGRAPHY: Chemical Separation Revealed By Color
Things that you will need for this activity:
1. Empty 2 liter pop bottle
2. Clothespin
3. 6 to 7 inch bowl
4. 12 inches of string
What to do and observe:
Take one piece of the filter paper. Make an ink blob at the bottom of the
paper then write your initials at the top. (You can make anything you want
besides your initials.) Get a clothespin hanger and an empty 2 liter bottle.
Cut the top 4 inches of the bottle off and discard. Put two small holes in
either side about one inch from the top then run the string through the holes
and tie a knot at each end (make sure the string is pulled tight across the
opening). Fill the bottom of the bottle with about 2 inches of water, hang
your slip of paper from the string with the clothespin into the water with the
ink blob a little above the water line. Observe the color bands that appear as
the water is drawn up into the paper. This will take about five minutes. (Make
sure only the bottom portion of the paper (1/4 inch) is in the water.)
So What?
This experiment shows that the black ink is a mixture of different
chemicals having different colors. The chemicals that dissolve faster in water
are carried further up the paper. Try the experiment with different colored
markers. Are the results the same?
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