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Osmosis Egg Lab

November 9, 2011 by jenni11 · No Comments · Uncategorized

The Effect of Different Salt Concentrations On The Rate Change of Osmosis In A Chicken Egg

Background Information:

If there are different types of water solutions and  an egg is placed in the water solutions, at least one of the eggs have to change. In a hypertonic solution, there’s more water concentration inside the cell and therefore the water diffuses out of the cell and the cell shrinks. In a hypotonic solution, there is less water concentration inside the test and the water outside of it diffuses through the cell membrane. Then there is also the Isotonic solution which means that the cell is in dynamic equilibrium, the concentration in the water and in the cell are the same. There is no change to the cell in the Isotonic Solution. All these solutions move from high to low concentrations.
The particles will move in a high to low concentration because that’s what happens in Passive Transport, it moves from high to low without the use of energy. The water in the Isotonic solution, the 0% salt solution, would not have change in its mass  because the concentration would stay the same, in dynamic equilibrium, inside and outside of the egg. In the Hypertonic, the 5% salt solution, the water in the egg would leave the egg and only the salt would stay in the egg and the egg would decrease its mass because it would have less water concentration. In the Hypotonic solution, the 15% salt solution, the egg would gain water concentration inside and the mass would therefore increase its mass.
Facilitated Diffusion is similar to both active and passive transport because they can both use a protein tho help them diffuse molecules and particles across the cell membrane. The difference between them is that in passive it uses no energy and it moves from high to low, but in active transport it requires energy and it moves from low to high concentration, moving against the concentration gradient.

Question:    How does the concentration of the solution affect the rate of osmosis on a chicken egg?

Hypothesis 1: If a chicken egg is placed into a beaker of 0% salt solution then the egg would stay in an isotonic solution and have the same mass because there would be the same concentration in and outside of the egg membrane.

Hypothesis 2: If a chicken egg is placed into a beaker of 5% salt solution then the egg will be in an hypertonic solution and the egg will decrease its mass more than what it started with because it has a lower concentration on the outside and the water inside the egg membrane would diffuse into the water solution.

Hypothesis 3: If a chicken egg is placed into a beaker of 15% salt solution then the egg will expand and it would enter into a Hypotonic solution because the salt solution would diffuse into the egg membrane causing it to increase its mass.

IDV: The independent variable is the salt solution

DV: The dependent variable would be the rate of the osmosis in the egg

Control: The estimated control variable is the 0% water solution.

`Constant:  The estimated constants would be the eggs, the amount of water in each beaker,
same type of beaker, same timing, and using the same weighing scale.


1. Fill 3 beakers with 150mL of water.
2. Put the 0% salt solution in one beaker, 5% salt solution in the second beaker, and 15% salt solution in the third beaker.
3. Get three designated timers for each beaker.
4. Take the initial mass of the egg
5. Place the egg in each beaker
6. Start the timer as soon as each egg is placed in each beaker
7. Carefully take the egg out of the beaker with a spoon after 4 minutes
8. Very carefully dry the egg with a paper towel so it won’t have excess water
9. Place it on a weighing boat
10. Place the weighing boat on the balance
11. Weigh the egg in grams
12. Record the measurement
13. Repeat steps 6-11 for 3 more trials

water solutions initial mass trial 1- 3 min. trial 2- 6 min trial 3- 9 min trial 4- 12 min Difference (Range)
0% salt 82.9g 83.3g“ 83.7g 84g 85g 2.1g
5% salt 86.2g 85.7g 85.5g 85.2g 84.3g 1.9g
15% salt 83.1g 82.5g 82.1g 81.6g 81.3g 1.8g


The purpose of this investigation was to see how different solutions affected the rate of osmosis on a chicken egg. In the lab, The Effect of Different Salt Concentrations On The Rate of Osmosis In A Chicken  Egg, there were three hypothesis for each water solution. For the 0% Salt Solution, the hypothesis stated that it would be in an Isotonic Solution and it would have no change to the mass therefore it would be in dynamic equilibrium. The second hypothesis, which was the 5% Salt Solution, stated that it would be the Hypertonic Solution and the mass would be smaller than its initial mass because the water inside the cell would diffuse out of the egg, from a low to high concentration. Hypothesis 3 stated that it would be in a Hypotonic solution and the mass would increase throughout the time. The water would move to the lower concentration inside the egg cell. These hypothesis were were not supported during this lab, only hypothesis #2 was supported.
The results in this egg lab indicated that the Hypotonic solution was the 0% salt solution water because as it shows in the table above the mass more than doubled. The difference was 2.1g, Stating that the water outside of the egg membrane was on a lower concentration, so it moved inside the egg where it was in a high concentration. The 5% and 15% Salt Solutions were both Hypertonic solutions because they both decreased in mass. In the 5% Salt solution it went from 86.2g to 84.3g. The difference was 1.9g, almost 2g decreases over time through out the experiment. The water in the egg membrane moved from the low concentration inside the cell to the high concentration outside the cell. This indicates how Hypothesis #2 was supported during this lab. Hypothesis #3 was also in a hypertonic solution because the egg also decreased its mass during the lab it went from 83.1g to 81.3g, which was also about 2 g of a difference. Only that the difference, as you can see on the table is actually 1.8g. The water in this solution moved from inside the cell, the lower concentration, to outside of the cell into the high concentration.
The qualitative data that was taken during the lab was that, as soon as the eggs were placed in the beakers, the 0% salt solution was the only one that was not floating at the top of the beaker. The 5% salt solution and the 15% Salt Solution were both floating at the top of the beaker. Based on these observations we determined that as soon as the 0% salt solution was placed in the beaker, the egg started to absorb the water causing the egg to get bigger in size. The other two eggs were floating because it’s mass was decreasing causing the egg to be lighter, therefore they floated on top. Osmosis was the type of passive transport that occurred during this experiment because it required no energy to have the water diffuse in and out of the egg and because the water molecules moved from a high to low concentration. The observed results were similar to facilitated diffusion because they moved from high to low and only some molecules were able to get pass the egg membrane. The difference was that it did not use a protein like in active transport nor did it use energy. Also, the diffusion did not go against the concentration gradient. Errors in the process included, that there might have been some left overs in the beakers from earlier labs, the eggs were not taken out of the beaker at the exact time, the eggs could have been from different places, and when of the eggs was placed, the timer didn’t start right away.
The facts clearly indicate that there was no Isotonic solution, the 0% salt solution was the only Hypotonic solution and the 5% and 15% salt solution were both Hypertonic. The experiment would have been more effective if there was different types of solutions, more time to have the experiment take place, and if there was at least 3 people in our group. There were many people that contributed to the Passive and Active Transport Theory. They were able to make us understand that passive transport was when molecules went from high to low concentrations and without any use of energy. Active transport went against the concentration gradient, which meant from low to high concentration and using ATP, energy. The experiment could be improved by the use of microscopes to be able to see inside the membrane or how the water slowly diffused through the membrane at different rates.

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