Osmosis and the Egg by HC120521114657

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									                                      Osmosis and the Egg

In this investigation you will use a fresh hen’s 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, graduated cylinder, white vinegar, clear Corn
syrup, distilled water, 400 or 250 mL beaker, parafilm or plastic wrap

Day 1 Procedure:

1.   Measure out 200mL of vinegar using a graduated cylinder and place it in a beaker.
2.   Gently place the egg in the jar being careful not to break the shell
3.   Cover the beaker with a piece a parafilm or plastic wrap
4.   Allow the egg and beaker to rest for 48 hours


Day 2 Procedure:

1. Observe what has happened to your egg and record it in figure 1 (data chart)
2. In a CLEAN 400mL beaker, measure out 200mL of corn syrup and place it in the beaker
3. Carefully remove your egg from the vinegar. IT IS VERY FRAGILE SO BE CAREFUL!
Very Gently rinse the egg off under SLOWLY running water.
4. Place the egg in the corn syrup
5. Cover the beaker with a piece of parafilm or plastic wrap.
6. Allow the beaker and egg to rest for 48 hours.
7. Using the graduated cylinder, measure the remaining vinegar and then discard it in the sink.
Record the volume of remaining vinegar in the chart.
8. Clean the empty beaker with SOAP, WATER and a BEAKER BRUSH.

Day 3 Procedure:

1. Measure 200mL of water using the graduated cylinder and add it to a CLEAN 400mL beaker.
2. Remove the egg from the syrup jar carefully and record observations of the eggs appearance
in the data chart.
3. Place the egg in the water and cover the beaker with a piece of parafilm or plastic wrap
4. Measure the volume of liquid that remains in the syrup jar using a graduated cylinder and
record the volume in the data chart.
5. Clean the empty beaker with SOAP, WATER and a BEAKER BRUSH
6. Prediction: Predict what you think will happen over the next 24 hours. Be sure to
consider the size of the egg and the volume of the water. Have the teacher check and initial
your prediction before you leave the lab.
Day 4 Procedure:

1. Remove the egg from the water and carefully and record observations of the eggs appearance
in the data chart. DISCARD THE EGG

2. Measure the volume of liquid that remains using a graduated cylinder and record the volume
in the data chart.
3. Clean the empty beaker with SOAP, WATER and a BEAKER BRUSH.

Data/Observation Chart

              Jar Volume Before Egg was           Volume After Egg        Egg Observations
                       Added                         was Added
Vinegar

Syrup

Water


Questions:

1. When the egg was placed in water, in which direction did the water molecules move? Is
water hypotonic, hypertonic, or isotonic to the egg?




2. On what evidence/data from the lab did you base your answer for #1?




3. When the egg was placed in the cornsyrup, in which direction did the water molecules
move? Is cornsyrup hypotonic, hypertonic, or isotonic to the egg?




4. On what evidence/data do you base your answer for #3?
5. If you were to place your egg in saltwater overnight, which direction would water move?
Is saltwater hypotonic, hypertonic, or isotonic to the egg?




6. What evidence would you have to support this hypothesis/prediction?




7. List at least three possible sources of error (human error or otherwise) in this lab.




8. This lab demonstrates the process of osmosis. What is osmosis? Does osmosis require
the cell to use energy?




9. Research Extension: Do some research (internet, other teachers, etc.), find out one way
in which osmosis or diffusion affects/impacts humans (medically, environmentally, etc.).
Be specific and explain HOW this occurs.

								
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