BioLab 3 - Osmosis

In this investigation you will use a fresh egg to determine what happens in osmosis. You will be measuring the amount of water that passes through the membrane lining the shell of the egg.

MATERIALS: fresh egg in shell, wax pencil, 200 ml graduated cylinder, 3 jars with covers, white vinegar, Karo sugar syrup, distilled water.

1. With the wax pencil, label the three jars: vinegar, syrup, water. Also put the number of your group on each jar.
2. Using the graduated cylinder, measure 200 ml of vinegar. Put it in the jar labeled "vinegar".
3. Place the egg in the jar. The vinegar must completely cover the egg. Cover the jar but do not seal tightly.
4. Allow the jar to stand undisturbed for 24 hours.

1. Observe what has happened to your egg. Record observations on the data sheet.
2. Using the graduated cylinder, measure 200 ml of syrup and pour it into the correct jar.
3. Carefully remove the egg from the vinegar. It is quite fragile now as the shell is dissolved. Very gently rinse the egg in water (removing any remaining egg shell) and place it in the syrup jar. Cover the jar but do not seal tightly.
4. Allow the jar to stand undisturbed for 24 hours.
5. Using the graduated cylinder, measure the amount of vinegar left in the vinegar jar. (If any vinegar has overflowed into the tray, include it in the measurement.) Record the volume of remaining vinegar on the data sheet.

1. Measure 200 ml of water and add it to the water jar.
2. Carefully remove the egg from the syrup jar. Record your observations of the egg's appearance on the data sheet.
3. Place the egg in the water jar. Cover loosely.
4. Allow the jar to stand undisturbed for 24 hours.
5. Measure the volume of liquid that remains in the syrup jar. (If any has spilled out, include it in the measurement.)

1. Remove the egg from the water and record your observations of its appearance. Discard the egg in the container provided.
2. Measure the amount of water that is left in the jar. Record in the data table.
3. Answer the questions on the data sheet.