Do A Science Experiment On Disintegrating An Eggshell

Eggs are commonly used in science class to demonstrate osmosis.

Science projects demonstrating the effect of osmosis can be conducted using an egg. Osmosis is the diffusion of a substance across a semipermeable membrane from an area of low concentration to an area of high concentration. An egg is used to illustrate osmosis because the shell has numerous pores that act as a membrane, and when the shell is disintegrated, you can place the egg in different solute concentrations to observe the effects of osmosis.

Instructions

Osmos

1. Obtain three eggs and place them in a beaker. Pour vinegar over the eggs and cover them. The vinegar will serve as an acid that dissolve the eggshells. Eggshells are composed of calcium carbonate, and calcium carbonate dissolves in acid.

2. Let the eggs sit in the acid until the eggshells are completely disintegrated. Vinegar usually takes several days to completely dissolve an eggshell. Therefore, carefully observe the eggs over a course of several days until the shells are gone.

3. Take the eggs out of the vinegar solution once the eggshells have dissolved. Obtain three new beakers, one containing water only, another containing isotonic sucrose solution and the remaining beaker containing one Molar sucrose solution. Make sure that you add the same amount of solution to each of the beakers.

4. Leave the eggs in the solutions for 12 hours. Remove the eggs, observe and record the results. You should notice that the egg that was placed in the water appears swollen. This has occurred because water moved from an area of low solute concentration (outside the egg) to an area of high solute concentration (inside the egg). The egg in isotonic solution should have remained the same size since the isotonic solution is equal to the solute concentration inside the egg. The egg placed in the one Molar solution should have shrunk since the water moved from an area of lower solute concentration (inside the egg) to an area of higher concentration (outside the egg).

Tags: solute concentration, concentration inside, from area, solute concentration inside, area high