MadSci Network: Edible/Inedible Experiments Archive

The cat's meow

Area of Science: Chemistry
Meant for at least Grade K-3 (age 5-7).
This experiment is edible.
An adult need not be present.

Overview:
Oil causes the food coloring to circulate in the milk making swirls of color

Equipment:

Milk (in a glass or single serving carton with the lid cut off)
Food colors
vegetable oil
a table to place the milk on
Safety:
The milk must not be disturbed for the experiment to work properly.

How to do the experiment:
Put milk in a glass or cut the lid off a carton. 2% or higher fat content works the best. Place one drop of each color of food coloring in each corner of the carton or near the sides of the glass. Place a drop of vegatable oil in the middle. Be careful not to move the glass or to shake the table. After a short time the colors swirl and mix, it looks really cool. Try it with different fat percentages and see how it affects the patterns or the rate of swirling.

Explanation:
This is caused because milk is mostly water and some fat. The oil is only soluble in the fat. The oil creates a current which causes the colors to circulate mix.

Useful References:

Further comments:
Sometimes it takes a little while for this to happen, but it will happen.


Experiment submitted on Fri Apr 18 09:40:12 1997 by:
Name: Charissa Detwiler
Institution: University of California Santa Barbara
Position: Undergraduate Student


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