Dye Chemistry
Subject Area: Chemistry
Grade Level: Middle School Chemistry
Lesson Title: Dye Chemistry
National Science Education Standards:
 Science as Inquiry: 5–8
 Properties and Changes of Matter: 5–8
 History and Nature of Science: 5–8
 Science in Personal and Social Perspectives: 5–8
Suggested Prior Knowledge: concepts of molecules, acids and bases, pH, chemical reactions,
and solutions
Purpose: To understand how dyes color things such as eggs or fabrics, to observe a chemical
reaction in which a dye bonds to a surface or fabric
Key Vocabulary:
dye—soluble colored compounds that react with, for example, egg shells or fabric, to impart
color
extract—a substance made by a part of a raw material, often by using a solvent such as
ethanol or water; a solution or infusion made by drawing out from any substance that which
gives it its essential and characteristic virtue
extraction—the process of obtaining something from a mixture or compound by chemical
or mechanical means
Objectives:
1. Students will investigate natural dyes and what colors they give to eggs or fabric.
2. Students will design and carry out an investigation to determine which natural products
will produce the desired color on eggs or fabric.
3. Students will draw conclusions concerning which sources produce which dyes.
Materials:
- Safety goggles
- Natural dye sources (attached list)
- Hard-boiled eggs (or cotton fabric)
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- Wax pencils or crayons
- Vinegar
- Sodium carbonate
- Coffee filters
- Hot plate
- Spoons
Procedure:
1. Begin with a discussion of the history of dyes. Dyes have been used to color fabric and other
things for thousands of years. Early Romans dyed wool fabric, and indigo (think blue jeans) has
been used as a dye since early Roman times. Natural and synthetic dyes are still widely used to
color fabrics, paper, and even skin (henna). Some dyes (like many sold in stores) just color the
fabric and wash out a little each time the fabric is washed. Other dyes chemically attach to the
molecules of the fabric, and can never wash out.
2. Discuss with students the concepts of chemical reactions, specifically reactions in which color
changes. Dyes are commonly used in the U.S. in many different ways. Synthetic dyes are used in
everyday foods for their bright colors and low cost; yet they are also currently being studied by
the FDA and other groups because of concerns that these synthetic dyes contribute or even cause
behavioral changes such as hyperactivity and inattention in children. These synthetic food dyes
are not just used in snack foods, they are in a surprising array of everyday “healthy” food choices
such as yogurt, macaroni and cheese, and pickles.
3. Explain that students will work in cooperative groups to design and carry out an investigation
into natural dyes that could be used (as they are in the U.K.) to replace these synthetic dyes in
our foods. Students will use these natural dyes to dye a hard-boiled egg. This is a good way to tie
into the spring season but this lesson can also be used with cotton fabric (handkerchief). Some of
these dyes will react better in acidic solutions and others in basic solutions. Begin with a leading
question, and follow up:
 How does a solute dissolve?
 How can we design an investigation to determine which of these natural products will
impart the brightest and most varied colors to our eggs/fabric?
 Could we also color paper or other kinds of fabric with these dyes?
 What effect does changing the acidity of the dye solution (adding vinegar or sodium
carbonate) have?
 What happens if we decorate the egg or fabric with crayon first?
4. Guide students to develop a hypothesis and identify the variables they will test. Work with
students to determine what will be their control and what will be the independent and dependent
variables in their experiments. Students should be limited to a specific number of dyes with
which to work. Students should determine a list of materials they will need to carry out their
investigation and they should develop an appropriate data table.
5. Ensure that students outline the steps of their procedure carefully. Work with students to
design a valid investigation into these natural dyes, a procedure similar to the one outlined in this
lesson plan or something of their own design. Some leading questions include the following:
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How will you extract the dye from the source?
How will you color the eggs?
Can we mix sources to get different colors?
Can we double dye (dye first with one color then again with a different color) to get
mixed colors?
Are there other ways to make designs on the egg/fabric?
6. Lab safety equipment and protocols should be followed. Caution students that these dyes may
also dye their skin and clothing. They should avoid getting the dye solutions on their skin or
clothing. Goggles are mandatory; gloves and aprons may be a good idea. Tie back hair and avoid
loose clothing near hot plates. T-shirts can often be used to pull over students’ clothing for
protection.
7. Some general procedures that could be used include the following:
a. Obtain several hard-boiled eggs to color.
b. Place four 400 mL beakers 2/3 full of water on hot plates and heat these to boiling. Add a
small amount (5 mL) of vinegar to each beaker to acidify the water.
c. Place a different natural dye source in each beaker to color the water.
d. Add one egg to each beaker of boiling dye.
e. Reduce heat to simmer for about 15 minutes. Longer boiling time will impart a deeper color in
most cases. Using more dye material may also give more color.
f. Some variations to try include the following:
 Leaving eggs in cold dye in a refrigerator overnight may give darker colors. This can be
done by the removing eggs from the dye solution, straining the dye solutions (a coffee
filter works well) and then putting the eggs back in the solution overnight.
 Coloring designs on the eggs with wax pencils or crayons before dyeing will leave parts
uncolored, for a batik effect.
 Altering the acidity of the dye solution may change the results. Students may even want
to see if they get the same or different results in a basic solution (add sodium carbonate).
g. Some follow-up investigations:
 Students can try using the dyes to color different materials such as various types of
fabrics (cotton, nylon) or even paper.
 Students may want to attempt to color-match an artificially dyed food, such as macaroni
and cheese or yogurt.
 Students can research products that are available here and in the U.K. to investigate what
dyes are used in similar products. The U.K. has stopped using a number of these synthetic
dyes in foods.
8. After students have finished their investigations, they may present their findings to their
classmates and compare their results with those of their classmates.
Additional Resources:
 http://www.flinnsci.com/Sections/Safety/safety.asp
 http://www.straw.com/sig/dyehist.html
 http://chemistry.about.com/od/holidayhowtos/a/eastereggdyes.htm
 http://www.chm.bris.ac.uk/webprojects2002/price/contents.htm
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http://en.wikibooks.org/wiki/A-level_Applied_Science/Colour_Chemistry/Dyes
http://www.pburch.net/dyeing/chemistry_reactivedyes_lesson.shtml
http://www.newsday.com/opinion/oped/opinion-danger-of-artificial-food-dyes1.2787500
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Natural Dye Sources
Color
Ingredients
Lavender
Small quantity of purple grape juice
Violet blossoms plus 2 tsp lemon juice
Red Zinger tea
Violet Blue
Violet blossoms
Hibiscus tea
Red wine
Blue
Canned blueberries
Red cabbage leaves (boiled)
Purple grape juice
Green
Spinach leaves (boiled)
Yellow
Orange or lemon peels (boiled)
Carrot tops (boiled)
Celery seed (boiled)
Ground cumin (boiled)
Ground turmeric (boiled)
Chamomile tea
Green tea
Brown
Strong coffee
Instant coffee
Black walnut shells (boiled)
Black tea
Orange
Yellow onion skins (boiled)
Cooked carrots
Chili powder
Paprika
Pink
Beets
Cranberries or juice
Raspberries
Red grape juice
Juice from pickled beets
Red
Canned cherries with juice
Pomegranate juice
Raspberries
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Student Worksheet Dye Chemistry
Experiment Title: _____________________________Date: __________Name: _____________
Student Hypothesis or Question:
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Materials:
Safety goggles
Water
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Safety Precautions:
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Procedure:
Wear Safety Goggles for all lab work.
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Data and Observations:
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Analysis of Data: _______________________________________________________________
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Conclusion: ___________________________________________________________________
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