Question to Explore:
What effect does an acid have on an egg?
Materials:
- one raw egg
- tall drinking glass/ mason jar
- vinegar
Procedure:
- Put your raw egg into a tall drinking glass/jar.
- Pour vinegar into the glass until the egg is covered. Option to mix food coloring into the vinegar.
- Put the glass aside so no one drinks and/or spills it.
- Let the egg soak for 1 week. Make some observations of any changes during the week.
- At the end of this time, rinse off the egg and pick it up. You should notice it feels slightly different than when you started. Shake it. Gently squeeze it.
- Test out your new creation in the sink by dropping it from a few inches and then some more. (Your egg may break)
You can also test this experiment out with different liquids from your kitchen. Some liquids to try out are Coke, Corn syrup, salt water, and olive oil)
Click the play button below to see a step by step video of this experiment by Hoopla Kidz Lab!
Follow up Questions:
- Why did the egg lose its shell?
- What makes the egg so rubbery?
- How high can your egg bounce before it breaks?
- What happens if you hold a flashlight up to the egg?
- Can vinegar turn other things rubbery? Why or why not?
Explanation:
The shell of an egg is made of calcium carbonate, which is a combination of carbons, calcium, and oxygen. When we place the egg in vinegar for a period of time, a chemical reaction takes place between the carbonate and the vinegar (similar to the reaction that occurs when we mix baking soda and vinegar, but less extreme). Notice the bubbles on the eggshell when it is placed in the vinegar! This is the acid in the vinegar reacting with the calcium carbonate in the shell. This reaction is producing a gas called carbon dioxide!
The chemical reaction slowly removes the shell from the egg. Once the shell is gone, the vinegar will cross over the semi-permeable membrane (through a process called “osmosis”) and slightly inflate the egg. The egg will become “pickled” and will harden. As the membrane gets tough, you are able to bounce the egg on the counter and roll it on the floor. However, the egg is not impermeable. It will still break if you puncture it or drop it from a high enough distance.
References:
Featured photo: https://littlebinsforlittlehands.com/naked-egg-experiment-rubber-egg-science/
Materials photo: https://www.fizzicseducation.com.au/150-science-experiments/kitchen-chemistry-experiments/create-a-naked-egg/