1. A raw egg
2. A glass jar or a glass container that you can put the egg in
4. Tape measure
1. Use the tape measure to measure the width of the egg and then record the measurement.
2. Place the egg in the jar.
3. Pour enough vinegar into the jar so that the egg is completely covered by the vinegar.
4. Record what happens to the egg when it is in the vinegar.
5. After a couple of hours remove the egg from the vinegar. Observe what happened to the egg.
|Egg in vinegar|
1. When you put the egg into the vinegar you should see tiny bubbles floating off the eggshell.
2. After a couple of hours you should see that the eggshell is soft and rubbery.
The bubbles which you saw when you put the egg in the vinegar are the by-products of the chemical reaction which happening between the vinegar and the eggshell. The eggshell contains a compound named calcium carbonate. This calcium carbonate is the reason why the eggshells become hard. Vinegar is originally a kind of acetic acid which can cause a chemical reaction with calcium carbonate. When we put the egg in the vinegar a chemical reaction occurs between the calcium carbonate residing in the eggshell and the acetic acid residing in the vinegar. The chemical reaction between calcium carbonate and acetic acid produces carbon dioxide gas. That’s why when you put an egg in the vinegar you see bubbles floating up from the eggshell. The chemical reaction produces carbon dioxide which takes the form of bubbles in the vinegar and goes upwards as it is lighter than vinegar. This reaction causes calcium carbonate to lose some part of it. That makes the eggshell a bit soft and rubbery. The longer you leave the egg in the vinegar the more soft and rubbery the eggshell will become until the eggshell is dissolved to nothing. Only a thin membrane will then cover the egg from the outside environment.
MORE EXPERIMENTS FOR YOU:
1. Try this experiment using different kinds of eggs.
2. Try this experiment using different acids (Careful to choose less powerful acids for this experiment. You can add water to make the acid less powerful).3. Leave the soft and rubbery eggshell outside on the environment. Will the eggshell be restored by reacting with the carbon dioxide in the air?