In science class we were learning all about osmosis and diffusion, and so that we could understand it better, our teacher, Ms. Silva gave us a very interesting project. The project was to be done in group of threes. Firstly, Ms. Silva took off the shell of the eggs for us, so that we could examine them in different kinds of solutions for some days. Our group could choose whichever solutions we wanted. The group assigned to me was Marina Silveira and Rodrigo Ussier. The two solutions we chose were corn syrup and distilled water. We had to put the two de-shelled eggs in each of the two cups which contained corn syrup in one of them, while on the other, distilled water. We were supposed to make observations and measure the eggs for each of the days. Some of the materials we used were:
-2 de-shelled eggs
-2 plastic cups
-a graduated cylinder
-80 mL of corn syrup
-80 mL of distilled water
-a ruler and a string to measure the circumference of the eggs
-weight scale to weigh the eggs
Predictions: One of our predictions were that the egg that was in the corn syrup was going to get smaller because the concentration of water inside it was bigger then the concentration outside of the egg. On the other hand, we thought that the egg in the distilled water was going to get larger since the concentration of water is more outside then inside since it’s 100% water/H20 in the solution, therefore no other solution could be as concentrated as water, thus why the egg would get larger. We predicted that the distilled water would have less liquid as well. Adding on to that, we thought that the egg dipped in corn syrup was going to get darker and sticky because of the dark and sticky substance that was added to the egg.
What did we do: On the first day, my team and I measured both eggs and took notes on their appearance, mass and circumference. Then, we added 80 mL of our substances to the cup the eggs were on, which in this case were corn syrup in one cup and distilled water on the other one. We let the eggs and the solutions react in a 24-hour period so that we could measure it again on the following day.
On the second day, my team and I measured both eggs again and took annotations as how it looked and how they changed. We let the eggs and solutions react again for a 24-hour period so that we could measure on the next day.
On the third day we measured the eggs yet again and we broke them in the middle to take notes on how they looked inside and compared our results with the other groups’ results; we had to average it to make a chart and a graph. Although, the chart/graph part was individual.
Tables and graphs of the final results:
Observations: Some of our observations were that before putting the egg in the solution, on Day 1, the eggs were yellow and a bit translucid; it was soft, humid and opaque. The eggs were “wrinkly” and the distilled water was very transparent and “liquidy” while the corn syrup looked very dense and was very sticky. After putting our eggs in the solutions, we noticed that the eggs sank a little bit.
On Day 2, we observed that on the egg that had the corn syrup solution there were air bubbles around the egg’s surface. The egg was even more “wrinkly” and it partially sunk- it floated more then before. While the corn syrup was more “watery” and had some particles floating in it. It was more yellow then orange. Still on Day 2, we noticed that the egg in distilled water also had air bubbles around the egg’s surface and it sank more. The egg was whiter and less “wrinkly”; while the water had no substancial difference.
On Day 3, we noticed that the egg in distilled water looked like a balloon filled with water and felt heavier; while the corn syrup egg was very opaque and “wrinkly” and the corn syrup was very “liquidy” and yellow. Still on Day 3, after opening the eggs, we noticed that the egg’s(in the corn syrup) shell was very brown and the yolk was very sticky because of the corn syrup and the sugar. The yolk was crystalized and rough(though inside the yolk was soft) and yellow. When we cut in half the other egg, the one in distilled water, it popped open, flying water everywhere. The shell was white and the yolk softer then the corn syrup’s egg’s yolk. It was also very less sticky.
Conclusion:
As for the amount of solution in the cups, for the corn syrup, the amount increased, from 80 mL on Day 1, to 86.5 mL on Day 2, to 79 mL on Day 3. The amount of solution in distilled water decreased. It started off with 80 mL as well on Day 1, then 71 mL on Day 2, and 60.3 mL on Day 2. Our prediction that the distilled water would have less liquid was correct.
What happened to the eggs was that in corn syrup, which had a lot of sugar and less H20 happened one of the processes now well known in our science class. Osmosis happened because of the low concentration of the H20 in corn syrup and high concentration of H20 in the egg, for it to balance out. The egg had proteins(amino acids) and thus why diffusion happened as well.
While the egg in distilled water, had less H20 then the water itself which was 100% pure water. The concentration in the water was higher then in the egg, therefore osmosis happened and diffusion also did because of the proteins in the eggs.
*The independent variables were the type of solution the egg was in and the dependent variable was the mass, circumference and the volume of liquid in the cup.
Osmosis/diffusion in real life: When we are thirsty, it’s because our cells have less water inside them. We need water for chemical reactions and if we don’t have enough water, chemical reactions can’t be performed. Water is essential to our body. When we do drink water, our cells have less water then the outside of the cell and osmosis happens. Osmosis is when water goes from a high to a low concentration. If there is more water on the outside of the cell, it goes to the inside, balancing it and making it equal. While diffusion, has to do only with solutes. An example is when an amino acid (since proteins are too big to pass) pass from a high to low concentration.
Possible errors: Some of the errors that could have happened in our procedure was that when we were measuring the eggs with the string, the person who did so(me in this case) could have measured at a different part of the egg; Water or corn syrup could have spilled; we could have not gotten all the water out of the cylinder after washing it to measure the following solution/could have not washed the cylinder which contained the previous solution affecting the results of the following solution; when comparing our answers with the other group’s they could have done something wrong as well or we could have done the average wrong;
As for materials, the cup could have been too small and could have squeezed the egg; the string that was used to measure the circumference of the eggs could have stretched a few more cm; the cylinder wasn’t washed well enough;
Evaluation: Overall, we had a lot of fun and I found all of this very interesting. I didn’t really understand the process of osmosis and diffusion before, although after that, I really did understand it more. My group was very helpful and I’m thankful to be put into a good group who works equally. We helped each other a lot and worked in teamwork- which is essential when participating in something like an experiment or a project. We really divided the tasks so that everyone could have something to do and so that each one would work equally. We even named our eggs: Nemayê and Bob!
As for fixing our errors we could compare our averages or maybe work it out more then one time(I did three times though); we could have tried not to make any liquids spill; we could have tapped the cylinder so that all the water could have gone out after washing- and we could have washed it twice to make sure it’s clean;
As for fixing our errors we could compare our averages or maybe work it out more then one time(I did three times though); we could have tried not to make any liquids spill; we could have tapped the cylinder so that all the water could have gone out after washing- and we could have washed it twice to make sure it’s clean;
This was an amazing experience which I learned a lot from, and hope to do more fun ones like this one in the future!
See you next time,
Débora Cunha
P.S.:
Some of the pictures:
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| Egg in distilled water on Day 3 |
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| Egg in corn syrup on Day 3 |
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| Yolk and egg shell of egg in distilled water after we cut it in half |
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| From left to right: Me(Débora Cunha), Marina Silveira and Rodrigo Ussier jotting down our observations of the eggs |
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| Shell and yolk of egg in corn syrup on Day 3- after we cut it in half |
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| From left to right: Me(Débora Cunha), Marina Silveira and Rodrigo Ussier after cutting our eggs in half |
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| Both eggs cut in half- distilled water and corn syrup |
