Question
How does liquid flow through an egg?
Materials
- 3 raw eggs
- 6 plastic cups or glass jars
- Food coloring
- Corn syrup
- Vinegar
What to Do
- Place each of the eggs in a cup of vinegar for 48 hours. Compare what the egg looked and felt like before and after the 48 hours.
- Carefully transfer the eggs to three different cups: one filled with plain water, one filled with water and food coloring, and one filled with corn syrup. Let the eggs stay in these cups for a few hours.
- Observe the differences between the eggs.
Observe the size of the eggs – are they bigger or smaller than before?
What is Happening?
The vinegar breaks down the egg shell exposing the cell membrane inside the shell. This membrane is permeable to water – in other words, water is able to flow through the membrane. Once the egg is placed in the new liquids osmosis takes place. Osmosis is the movement of water from areas of higher concentration to areas of lower concentration. The membrane of the egg allows water to pass through without letting the other parts of the egg out. This is how the cells in our body work. Since there is a higher concentration of water outside of the egg when placed in a cup with plain water and water with food coloring, the water flows into the egg causing it to get bigger. Since the concentration of water is lower in the corn syrup than in the egg, water leaves the egg through the cell membrane causing it to shrink and shrivel.
Activity add-ons:
Try this experiment with salt water of varying concentrations. How does this affect osmosis?