Egg Science

What are we doing?

Removing the shell of a raw egg and making the egg change in size.

What do we need?

  • Glass jar with lid
  • 1 raw egg
  • Clear vinegar
  • Measuring tape
  • Corn syrup

What do we do?

  1. Measure the circumference around the center of the egg and record your findings.
  2. Place the whole egg into the glass jar.
  3. Cover the egg with clear vinegar and place the lid on the jar.
  4. Observe immediately and for the next three days.
  5. After three days, remove the egg and measure its circumference. Did its size change? What else changed?
  6. Clean the jar and replace the egg inside of it.
  7. Fill the jar with corn syrup.
  8. Observe the egg for the next three days. How has it changed?

What’s going on?

Immediately after we place the raw egg in the vinegar, bubbles start to form around it. After 24 hours the shell will be gone and portions of it will be floating on the surface. The egg remains intact because of the thin see-through membrane that is normally between the shell and the egg white. Also, the size of the egg has slightly increased.

Vinegar is made of acetic acid and eggshells are made of calcium carbonate. Acetic acid reacts with the calcium carbonate and dissolves the shell. Next, the water from the vinegar moves through the membrane into the egg because the membrane is semi-permeable. What this means is that some small particles can pass through the microscopic holes in the membrane, but other larger molecules cannot. Water molecules are small enough to move through the membrane and balance the water levels on each side.

Next, we placed the swollen egg into the corn syrup for three days and it shrunk in size. This is also due to the semi-permeability of the membrane. There is very little water in corn syrup and the egg white contains a lot of water. So the water in the egg white moves through the membrane into the corn syrup to balance the water concentration and the size of the egg shrinks.