20 Minute Labs: Naked Egg, Big Egg, Small Egg

MAKE A NAKED EGG?!

With Easter right around the corner, you may be boiling and dying eggs.

Have you ever eaten a hard-boiled egg? They're pretty delicious, and making a boiled egg is kind of a neat experiment in itself. When it's boiled, you can peel off the shell and the egg inside keeps its shape!

But did you know that you can make an egg shell disappear - while the egg inside keeps its shape - with no cooking involved?

In this week's 20 Minute Lab, we'll make a naked egg using a few things from around the house.

Bonus Experiment! We'll also go a bit further and change our naked egg's shape! We'll make it bigger and smaller by changing the solutions the eggs are soaked in. Remember though, these eggs aren't for eating - they would taste disgusting! Remember, we never eat our science experiments! ;)

Just an FYI: The hands-on time involved in these experiments is very short, but there's a lot of waiting time. Be prepared for the science to work its magic overnight while you sleep! 

What You'll Need

• 2 small, wide-mouthed glasses
• 2 eggs (fresh uncooked eggs in their shells)
• about 4 cups white vinegar
• 2 spoons
• 2 cups water
• food coloring (optional)
• 2 cups corn syrup

Let's Get Started!

Naked Egg

1. Place one egg in each glass. 
2. Pour the vinegar into each glass, making sure to cover the egg by about half an inch.
3. To prevent the eggs from floating up, place a spoon over them. Note: You can cover the glasses to reduce the vinegar smell!
4. Leave the glasses undisturbed for about 24 hours.
5. Remove the eggs and rinse them under running water.
6. Gently rub the eggs until the shell is completely gone. Be careful, the eggs will be slippery!

 

Troubleshooting:

If your egg's shell is still hard after 24 hours, you may need to leave it for another day...

WHAT'S GOING ON?

What do you see? Where did the shell go? Does your egg feel rubbery and bouncy? How did that happen?

The shell of an egg is made of calcium carbonate. Vinegar contains acetic acid.

When the acetic acid in the vinegar comes in contact with the calcium carbonate in the egg shell, a chemical reaction happens, which dissolves the egg shell!

So that explains why the shell disappeared, but what keeps the egg from oozing everywhere?

Just under the eggshell is another type of covering called a membrane. A membrane is sort of like a thin skin. The vinegar doesn't affect the membrane, so it remains intact and holds the egg together. Pretty cool, right?

BONUS EXPERIMENTS

Big Egg, Small Egg

1. Pour the vinegar out of the glasses and rinse them out.
2. Place one naked egg in each glass.
3. Add water to one of the glasses so it just covers the egg. (You can also add some food coloring to this glass to keep track of which one is water.)
4. To the other glass, add corn syrup. (Note: The egg will float, but don't worry, that's OK. The syrup is denser than the egg!)
5. Leave the experiment for another 24 hours.
6. Remove the two eggs and compare sizes. Which egg is bigger?
7. For fun, pierce the big egg with a needle (over the sink) and watch a thin stream of liquid squirt out of the hole!

WHAT'S GOING ON?

Did your egg in the water get big? Did your egg in the corn syrup get small?
Wow! Why did that happen?

Well, first, let's talk about that skin-like membrane of the egg. This thin layer actually has tiny holes in it, which allow for certain things to move in or out.

Picture a fence with holes in it. You might be able to push a tennis ball through, but a basketball wouldn't fit.

In a similar way, small water molecules can move through the egg's membrane, but the larger sugar molecules in the corn syrup cannot fit through the tiny holes. 

This helps explain why the egg in the plain water glass grew larger. The concentration of water is higher in the glass than inside the egg. This means that water molecules move from the glass through the membrane into the egg - making it bigger! 

In the corn syrup glass, the concentration of water is higher inside the egg than in the corn syrup. This means that the water molecules move out of the egg, through the membrane, into the corn syrup. And the egg shrinks!

SHARE WITH US!

Let us know how your experiments turned out! Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

For more exciting experiments, check out our Yellow Scope science kits on the Shop tab of our website!