Introduction: The objective of this experiment is to demonstrate osmosis by using an egg as a model. In order for this to happen the vinegar will make the eggs shell disappears. The reason for this is because vinegar has acetic acid and the shell has calcium carbonate, when these come into contact it produces carbon dioxide. This is the reasoning for the little bubbles when the egg is first put into the vinegar. After the shell discinigrates it will become rubbery from the acetic acid, at this point the egg could very well bounce. | |
Hypothesis: The hypothesis made for this experiment would be that the egg will grow in width after sitting in each solution for a certain length of time. Materials: To do this experiment, these materials will be needed: 1 egg in their shells, water, Corn syrup, vinegar, clear jar or container with a lid, measuring device, paper towels, your worksheet and a writing utensil. Methods: On Day 1 The first step should be to get your container or jar. Next, measure the egg by the width not length, and record the results in the data table.
Now carefully place the raw measured egg into the jar or container and pour vinegar over the egg until it is covered completely. Cover the jar or container with a lid or foil. Then let the egg sit in the container until the hard outer layer is completely removed, about 24-48 hours. On Day 2 Take of the lid to either the jar or container and pour out all of the vinegar. Carefully remove the egg from the jar or container and rinse under gently running water. After rinsing of the egg, record the new characteristics of the egg, and measure the width of the egg. Record the information on the worksheet.
Place the egg in a clean container or jar. Carefully fill the container or jar with corn syrup, and cover the jar or container with a lid or foil and let sit for 24-48 hours. On Day 3 Take of the lid to either the jar or container and pour out all of the corn syrup. Carefully take out the egg and rinse it under gently running water. Again record the new characteristics and measurements of the egg of the worksheet. Fill a clean jar or container with water, place the egg in the container and cover with a lid or foil, and allow it to sit for 24-48 hours. On Day 4
Take the lid off of the container or jar and pour out all of the water. Remove the egg and rinse under slow running water. Record the final characteristics and size of the egg in the worksheet. Results: The egg was measured at 14. 5 cm before the experiment was started. After 24 hours of sitting in the vinegar the eggs outer shell diapered and clear coating was present. The egg then measured at 16 cm after sitting in vinegar. On day three the egg had been removed from the corn syrup. The egg had shrunk to 13. 2 cm. the egg was then placed in water for 24 hours Discussion and Conclusion:
The hypothesis was to be fully correct. According the hypothesis the egg should have grown after being in each solution. The egg shrank and while it also grew, after being in the solutions. The vinegar and the water caused the eggs to grow in size; whereas the syrup caused the egg to shrink in size. In this lab the observer was to suppose to be able to demonstrate osmosis by using an egg as a cell model. The observer learned how to be patient and to follow directions from the beginning to the end. The observer also learned how hypertonic and hypotonic solutions work in osmosis.
If you do not allow the egg to sit in the solutions for the full 24-48 hours the experiment will not work and you will have to start over. This lab did not require repetition. Questions: 1. Is the egg’s membrane permeable to water? Cite your evidence. 2. Was the egg in a hypertonic or hypotonic environment which in the corn syrup? What is the basis for your answer? The definitions for hypertonic and hypotonic according to dictionary. com is: Hypotonic- When a cell is placed in a hypotonic solution, the water diffuses into the cell, causing the cell to swell and possibly explode.
Hypertonic- When a cell is placed in a hypertonic solution, the water diffuses out of the cell, causing the cell to shrivel. The egg shrank during the corn syrup. This showed that the syrup was hypertonic to the inside of the egg, making all of the water to come out of the egg. The eggs size grew during the water and the vinegar part, this proved to be hypotonic in the egg, because the egg absorb the liquid into its self. 3. Describe what it means to be selectively permeable and how the egg’s membrane exhibited this characteristic.