This page contains full project details. For the summary, please see the Project Summary.
Science Fair Project Description
Discover this fascinating egg experiment with vinegar that makes a bouncy egg! Watch what happens to the shell and the inside of the egg! You'll learn how acid and base chemical reactions and even protein denaturation works!
Hypothesis
The hypothesis is that the vinegar (acid) will react with the calcium carbonate (base) in the egg shell, and the vinegar reacts with the proteins in the raw egg.
Overview
Acids and bases are different chemical compounds. When we mix an acid with water, it makes hydrogen ions. When we mix a base with water, it makes hydroxide ions. Hydrogen ions and hydroxide ions cause different kinds of chemical reactions. We can measure how acidic or basic something is by checking its pH level. If it's between 1 and 6, it's an acid. If it's between 8 and 14, it's a base. If it's 7, it's neutral.
Egg shells are made of calcium carbonate, which is a base. Vinegar is made up of acetic acid. When we put them together, the base in the egg shell reacts with the acid in the vinegar. The acidic vinegar breaks down the basic calcium carbonate in the egg shell. The egg shell dissolves and makes bubbles of carbon dioxide gas.
At the same time, the acidic vinegar also reacts with the protein inside the raw egg. The acid denatures the egg protein, making it all tangled up. This makes the egg feel rubbery.
Place one egg in each jar. Label one jar "vinegar", and the other "water".
Pour enough vinegar in the "vinegar" jar to cover the egg.
Pour enough water in the "water" jar to cover the egg.
Place the jars in a safe place where they will not be disturbed.
After 1 day, check the jars. What do you see?
After 2 days, check the jars again. What do you notice about the egg in vinegar and the one in water? If the egg shell hasn't completely dissolved, continue the experiment for another day.
Results
The egg placed in vinegar had bubbles on the surface of the egg shell. Then the egg shell started to dissolve. The egg placed in water did not dissolve. The most interesting observation was that the egg became rubbery after a few days!
Conclusion
The acidic vinegar reacts with the basic eggshell, creating carbon dioxide bubbles and eventually dissolving the eggshell. The acid-base chemical reaction leads to neutralization when all the acid and base have reacted with each other. The acidic vinegar also reacts with the egg protein, causing the protein to tangle up. This is called protein denaturation, which makes the egg rubbery.
Also consider
Variations of this experiment could include testing different acids, such as lemon juice or orange juice, boiling the egg before adding it to the vinegar or soaking the egg in vinegar with baking soda.
Related videos
These videos explain the science behind this project and demonstrate key concepts used in the experiment.
Be prepared for a surprise when a raw egg soaks in vinegar! Discover the science behind this surprising chemistry experiment!
Add another variation to the rubbery egg experiment by adding a hard boiled egg to vinegar! What do you think will happen? Follow along with this video from the New Mexico Museum of Space History!
