Color Changing Milk Lab
Science
Background—Milk is mostly water but it also contains vitamins, minerals, proteins, and tiny droplets of fat suspended in solution.
Fats and proteins are sensitive to changes in the surrounding milk. When you add soap, the weak chemical bonds that hold the fats
and proteins together in solution break and rip apart. Soap molecules combine to form a micelle, or cluster of soap molecules, that
surround the fat molecule. These micelles distribute the fat throughout the milk.
Materials
Dinner plate with a little whole milk in it
Red, Yellow, Green, & Blue food coloring
Dawn dish washing liquid
Cotton swab
Procedure—
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Read the entire lab.
Set up your lab notebook to do the lab.
Make a Hypothesis about what you think will happen.
Show your notebook and the notebook of your partner to your teacher to get approval to begin.
Get a dinner plate with a little whole milk in it. Carry it carefully
Put it on your lab station and let the moving milk settle for exactly three minutes.
Ask your teacher to drop in two drops of each of the four colors of milk according to the pattern on the board.
Get a cotton swab and soak one end completely in dish washing liquid by twirling it and rubbing off the excess.
Carry it back to your desk.
When your back, wait until your team is all watching and dip the cotton swab into the center of the 4 colors.
Play with your setup then write up your “Results” and “Conclusion”
Required Components:
Pre-lab
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Manipulated variable
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Responding variable
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Hypothesis
Post-lab
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Results
b.
Analysis
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Conclusion
Buy some clues to your Results and Conclusion-------over----
Results & Conclusion tips; It becomes a free-for-all! The molecules of protein and fat bend, roll, twist, and contort in all directions.
The food color molecules are bumped and shoved everywhere, providing an easy way to observe all the invisible activity. This
rapidly mixing fat and soap causes swirling and churning where a micelle meets a fat droplet. When the micelles and fat droplets have
dispersed throughout the milk the motion stops, but not until after you've enjoyed the show! There's another reason the colors explode
the way they do. Since milk is mostly water, it has surface tension like water. The drops of food coloring floating on the surface tend
to stay put. Liquid soap wrecks the surface tension by breaking the cohesive bonds between water molecules and allowing the colors
to zing throughout the milk. What a party!