| Your Fun Family - Science |
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The Rubber Egg
Materials you will need:
• A Sink
• Paper Towels
• White Vinegar
• A Hard-Boiled Egg
• A Clean Glass Jar and Lid
• A Sink
• Paper Towels
• White Vinegar
• A Hard-Boiled Egg
• A Clean Glass Jar and Lid
Experiment
1. Place the egg in a tall glass or jar and cover the
egg with vinegar.
1. Place the egg in a tall glass or jar and cover the
egg with vinegar.
2. Look closely at the egg. Do you see any bubbles forming on the
shell? Leave the egg in the vinegar for a full 24 hours.
3. It's time to change the vinegar on the second day. Carefully pour
the old vinegar down the drain and cover the egg with fresh vinegar.
Place the glass with the vinegar and egg in a safe place for a week,
that's right, 7 days! Don't disturb the egg but pay close attention to
the bubbles forming on the surface of the shell (or what's left).
4. One week later pour off the vinegar and carefully rinse the egg with
water. The egg looks translucent because the outside shell is gone!
The only thing that remains is the delicate membrane of the egg.
shell? Leave the egg in the vinegar for a full 24 hours.
3. It's time to change the vinegar on the second day. Carefully pour
the old vinegar down the drain and cover the egg with fresh vinegar.
Place the glass with the vinegar and egg in a safe place for a week,
that's right, 7 days! Don't disturb the egg but pay close attention to
the bubbles forming on the surface of the shell (or what's left).
4. One week later pour off the vinegar and carefully rinse the egg with
water. The egg looks translucent because the outside shell is gone!
The only thing that remains is the delicate membrane of the egg.
How does it work?
Let's start with the bubbles you saw forming on the shell. The bubbles
are carbon dioxide gas. Vinegar is an acid called acetic acid - CH3COOH -
and white vinegar from the grocery store is usually about 5% solution.
Egg shells are made up of calcium carbonate. The vinegar reacts with
the calcium carbonate by breaking the chemical into its calcium and
carbonate parts (in simplest terms). The calcium part (free ions of
calcium float around in the solution) while the carbonate part reacts to
form the bubbles that you see. Some of the vinegar will also sneak
through the egg's membrane (permeate the membrane) and cause the
egg to get a little bigger. That's why the egg is even more delicate if you
handle it. If you shake the egg, you can see the yolk sloshing around in
the egg white. If the membrane breaks, the egg's insides will spill out
into the vinegar. Yes, you've made a pickled egg but let's save these
little delicacies for the guy at the gas station who wants to reach in and
pluck one out of his pickle jar in exchange for your crisp dollar bill. This
is interesting... allowing the egg to react with the carbon dioxide in the
air will cause the egg to harden again.
Let's start with the bubbles you saw forming on the shell. The bubbles
are carbon dioxide gas. Vinegar is an acid called acetic acid - CH3COOH -
and white vinegar from the grocery store is usually about 5% solution.
Egg shells are made up of calcium carbonate. The vinegar reacts with
the calcium carbonate by breaking the chemical into its calcium and
carbonate parts (in simplest terms). The calcium part (free ions of
calcium float around in the solution) while the carbonate part reacts to
form the bubbles that you see. Some of the vinegar will also sneak
through the egg's membrane (permeate the membrane) and cause the
egg to get a little bigger. That's why the egg is even more delicate if you
handle it. If you shake the egg, you can see the yolk sloshing around in
the egg white. If the membrane breaks, the egg's insides will spill out
into the vinegar. Yes, you've made a pickled egg but let's save these
little delicacies for the guy at the gas station who wants to reach in and
pluck one out of his pickle jar in exchange for your crisp dollar bill. This
is interesting... allowing the egg to react with the carbon dioxide in the
air will cause the egg to harden again.
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