
Making
Rubber
Eggs
This is a really
cool science activity that involves dissolving egg shells and then
experimenting with the membrane that remains around the egg. It does
take several days and a few changes of the vinegar but the results are
worth the wait. It also makes good use of those extra eggs grandma
bought for preparing the holiday dinner.
You will need:
Eggs, small jars,
vinegar, and
corn
syrup .
Now try this:
-
Place whole egg
inside the small glass jar (you may use a hard boiled egg or
uncooked egg, I prefer the uncooked egg).
-
Completely cover
the egg with vinegar. Observe tiny bubbles forming on the egg.
-
Allow the
vinegar-egg mixture to react for at least two days. Replace the
vinegar every day.
-
Feel the egg, if
it feels "rubbery" remove the egg and rinse carefully under water.
-
Play a little
with the egg, squeeze it lightly. Be careful if the egg is not
cooked it will break apart easily.
-
Place the
"rubbery" egg back into the glass jar and completely cover with corn
syrup.
-
Allow the
syrup-egg mixture to "react" for at least one day. Remove egg and
rinse and observe how the egg has changed.
What is happening?
The vinegar is a
weak acid solution called acetic acid. This acetic acid dissolves the
calcium
carbonate egg shell. What remains on the egg is just it's membrane. This
membrane will allow water molecules to pass through. When the egg is
placed into corn syrup, the water molecules in the egg white passes
through the membrane into the corn syrup, causing the egg to get
smaller. Try putting this egg back into water, what happens?
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