Rubber+Egg

 Rubber Egg

This experiment answers the age-old question... Which came first, the rubber egg or the rubber chicken? It's easy to make a rubber egg if you understand the chemistry of removing the eggshell with vinegar. What you're left with is a totally embarrassed naked egg and a cool piece of science.

Materials - Raw egg - tall glass - white vinegar - Patience

 * 1) Place the egg in a tall glass and cover the egg with white 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. You've successfully made an egg without a shell. Okay, you didn't really make the egg-- the chicken made the egg-- you just stripped away the chemical that gives the egg its strength.

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. This is interesting... allowing the egg to react with the carbon dioxide in the air will cause the egg to harden again. http://www.stevespanglerscience.com/experiment/naked-egg-experiment