Soaking an egg in vinegar produces what is known as a “naked egg,” which is an egg without a shell. The vinegar dissolves the shell but leaves the membrane that holds the egg intact. This experiment provides a fascinating way to observe chemical reactions and the anatomy of an egg. You will see the membrane that acts as an additional defense for the egg. You can also watch the eggshell, comprised mostly of calcium carbonate, turn into aqueous calcium, water and carbon dioxide through the chemical reaction with vinegar, which is an acid.
Main ExperimentStep 1
Place an egg inside a large glass container, such as a beaker or jar. If you want to make more than one naked egg, make sure the eggs do not touch inside the container.
Pour enough vinegar into the jar to cover the egg completely. The egg might float to the top, but the vinegar should still cover most of the egg.
Observe what happens to the egg. You will notice tiny bubbles of carbon dioxide around the eggshell. The carbon dioxide is released during the chemical reaction taking place between the eggshell and the vinegar.
Set your jar aside and wait 12 to 24 hours for the eggshell to dissolve. You might notice a white froth at the top of the vinegar.
Pour out the vinegar carefully and catch the naked egg in your hand. You may also use a wooden spoon to remove the egg, but this method might cause it to break. If a small amount of white eggshell still remains on the egg, you can lightly wipe it off with your fingers. If the shell has not dissolved enough, place the egg in a fresh jar of vinegar for another 12 to 24 hours.
Additional ExperimentsStep 1
Watch your naked egg get bigger by placing it in a jar filled with water. The water will move through the membrane and into the egg through a process called osmosis. Try soaking the egg in water with food coloring to make the egg a different color.
Experiment with a few naked eggs to see which liquids make the egg swell bigger and which ones make the egg shrivel up. Put the egg in corn syrup, salt water, vegetable oil or other liquid. Substances like corn syrup don’t have much water, so it will make the egg shrink. Try putting the egg back into a jar of water and observe if it gets bigger after shrinking inside the corn syrup.
Test the strength of your naked egg by bouncing it on a hard surface. First try bouncing the egg from an inch away from the surface. Then gradually bounce it farther away from the surface -- at which distance does the membrane break? Does making the egg bigger or smaller with water or other liquid affect the membrane strength?
Items you will need
- Raw Eggs
- Glass jar or beaker
- Take the naked egg outside when testing the membrane strength to avoid an indoor mess.
- Wear safety goggles and gloves throughout the experiment.
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