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Green Eggs & Ham
When you were little, you probably read the Dr. Seuss book Green Eggs &
Ham. Here's a little pH trick to make some green eggs just like in the book.
Materials:
- Frying pan and stove
- Egg
- Red cabbage (it's called red, but it looks purple!)
What to do:
 - Chop a 1/2 cup of cabbage, cover it with boiling water, and let it sit
for 10 minutes until the water is dark purple. Strain out the cabbage.
- Crack an egg and separate the egg white from the yolk by carefully
pouring the egg from one half of the shell to the other over a bowl. (Or you
can pour the egg into a slotted spoon over a bowl instead.) Set the yolk
aside.
- Mix a little cabbage juice in with the egg white. What happens?
- Grease the pan and let it heat up a little, then pour the egg white in.
- Set the yolk in the middle of the egg white and finish cooking!
What's happening:
Red cabbage contains pigments called anthocyanins, which change colors when
they come in contact with acids (low pH) or bases (high pH), making them a natural pH indicator.
When the cabbage juice comes in contact with an acid (like vinegar) it will turn
red, but when it is mixed with a base it will turn bluish-green. What does this
project tell us about egg whites, then? Egg whites are basic
(also called alkaline) and so they turn the red cabbage juice green.
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