How Much of a Difference Can 24 Hours Make?
My lab was based on one very important question, how can the weight of potatoes change if
they are submerged in two saline solutions (1.0M and 0.5M) for twenty-four hours. The experiment requires six pieces of potatoes, cut into two inch rectangular pieces. It also requires an electric scale to measure the weight of the potatoes. The last thing required is two solutions that are in beakers, one must have a 1.0M saline solution, and the other must have a 0.5M saline solution. While doing the research for this project, I produced my hypothesis, I believed that if the three potatoes in the 1.0M solution were submerged all night, then they would loose more weight due to the overwhelming amount of salt in the saline solution. The water from the potato would exit, causing a notable amount of weight loss. This was my hypothesis because of the amount of water that would leave the potato when osmosis was taking place. For my hypothesis along with the experiment, I found a few websites to be crucial to my understanding of osmosis/diffusion and the process that would be taking place to the potatoes. An article that benefitted me was an article called ‘’Osmosis in Potatoes’’ by Claude E. Phillips Herbarium, this source gave important information to better my background information going into the experiment. I learned that the water in the potato moved outwards due to the high amount of salt in
My prediction is that as the concentration increases, the potato cell will lose more weight. This is because of the osmosis of water particles from the potato cell cytoplasm to the solution, resulting in a loss of weight. As the concentration decreases, the potato will lose less weight until a certain point where the osmosis of particles in and out of the potato cells will be equal. I also predict that as the salt
Osmosis is the diffusion of water across a membrane to create an equilibrium between the levels of concentration of a solute both inside and outside the cell. In this case the solute will be sugar as the potato core will be immersed in sucrose solution.
Though the theory following the hypothesis is correct and the experiment was carried out with as much attention as possible in a high school laboratory, the results obtained were still indicative of a few errors and did not support the predicted hypothesis. From the results obtained it can be concluded that as the concentration of sucrose increases the average percentage change in mass decreases. This is because the salt concentration inside the potato cubes of 10%, 15% and 20% concentration is less that in the salt concentration on the sucrose solution, thus the three cubes submerged in the 10% - 20% concentrated solution lost mass (hypertonic). However the cube submerged
By definition, osmosis is the diffusion of water across a selectively permeable membrane in response to gradients of concentration, pressure, or temperature (G. Audesirk, T. Audesirk, B. Byers). Diffusion is the passive movement of molecules or particles along a concentration gradient, or from regions of higher to regions of lower concentration (Diffusion). In the experiment, osmosis and diffusion occurred where the results indicated a change in mass when the egg was placed in different concentrations of corn syrup solution. My hypothesis stated that if the concentration of the solute is lower than the solvent, then the egg will shrink in size. With a majority of the results decreasing in weight, my hypothesis was proven to be correct.
Osmosis is defined as the tendency of water to flow through a semipermeable membrane to the side with a lower solute concentration. Water potential can be explained by solutes in a solution. The more positive a number is more likely it will lose water. Therefore should water potential be negative the cell the less likely it will lose water. In using potatoes the effects of the molarity of sucrose on the turgidity of plant cells. According to Clemson University, the average molarity of a White potato is between .24 M and .31 M when submerged in a sorbitol solution. This experiment was conducted with the purpose of explaining the relationship found between the mass in plants when put into varying concentrations of sucrose solutions. Should the potatoes be placed in a solution that contains 0.2M or .4M of sucrose solution it will be hypotonic and gain mass or if placed in .6M< it will be hypertonic and lose mass instead. Controlled Variables in this lab were: Composition of plastic cups, Brand of Russet Potatoes, Brand of Sweet Potatoes and the Temperature of the room. For independent variable that caused the results recorded it was the different Sucrose concentrations (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M). The dependent variable was the percentage change from the initial weighs to the final. The cup with .4 molarity was the closest to an isotonic solution and was used as the control group for the lab. Water potential is the free energy per mole of water. It is
Van’t Hoff’s Law suggests that the osmotic potential of a cell is proportional to the concentration of solute particles in a solution. The purpose of this experiment was to determine if there are any differences between the osmolalities, the no-weight-changes of osmolalities, and the water potentials of potato cores in different solutions of different solutes. The percent weight change of the potato cores was calculated through a “change in weight” method. The potato core’s weight was measured before and after they were put into different concentrations of a solute for 1.5 hours. In our experiment, there were no significant differences from the osmotic potentials of our results and the osmotic potentials of other scientists work. Ending with chi square values of 2.17 and 2.71, and p values of 0.256 and 0.337, concluding that there is no difference in water potentials of potato cores in different solutions of different solutes at varying concentrations.
In conclusion, the potato cube with the highest surface area to volume ratio (the 1x1x1 cube) had the fastest rate of diffusion as it had the largest percentage increase in mass. While all the other cubes of potato had larger increases in mass at face value compared to the smallest cube, the smallest cube had the largest overall gain in percentage. The results support my hypothesis that the smallest cube will have a higher rate of osmosis because it has a proportionally larger amount of surface area compared to its volume.
The solution had a higher concentration of water molecules than the potato itself. This causes the water to move from the 0.0 M solution into the potato cells through osmosis. The water movement causes the mass to increase as well as make the potato to appear firmer. The cells enlarge and become more filled with water, which causes them to potato to appear firmer. However, it is also seen in the weight gain of the potato in the results section.
The potato cells, took in, or gave out the water depending on the concentration of the solution it is surrounded in. The results were fine and by looking at the mass measured before the experiment, you can see that there is no reading which seems to be out of the line. As the weights before the experiment range between 2.31g and 2.46g, this tells us that the potato pieces were cut well, and I believe accurate enough. The results show that: - Osmosis actually took place in the experiment.
Showing an example of diffusion with the water molecules equally back and forth the semi-permeable membrane of the potatoes and the saucer of water. The hypertonic solution of salt water has given an example of osmosis. The water molecules passed through the semi-permeable membrane out of the potatoes but weren’t able to get back in as easily due to the salt blocking the membranes passage. This left the potatoes in the salt water saucer feeling flexible and spongy almost leaving the potato a little
In conclusion when the molarity level was at 0 and at .2 the potatoes had gained mass so therefore they were placed in a hypotonic environments. When the molarity level was .4 and above the potatoes loss mass so therefore they were placed in hypertonic environments. So the different in concentrations does change the mass of the potatoes because they determine the osmosis environments.
The purpose of this experiment was to investigate the effect of the change in concentration of sucrose on the rate of osmosis in cylinders of potatoes.
If you put tap water instead of the salt solution, we know that the mass of the potato will increase, we all know that happens because the water actually has a more fragile concentration than the potato (due to the water moving into the “spongy” membrane because of osmosis.) I believe if the potato is in a higher concentrated (hypertonic) solution then the mass will decrease because the potato has less concentration than the actual solution so, the water will go through the “spongy” membrane into an even stronger solution.
Osmosis is the movement of water molecules from high concentration to low concentration through semipermeable membranes, caused by the difference in concentrations on the two sides of a membrane (Rbowen, L.). It occurs in both animals and plants cells. In human bodies, the process of osmosis is primarily found in the kidneys, in the glomerulus. In plants, osmosis is carried out everywhere within the cells of the plant (World Book, 1997). This can be shown by an experiment with potato and glucose/salt solution. The experiment requires putting a piece (or more) of potatoes into glucose or salt solution to see the result of osmosis (a hypertonic type of solution is mostly used as it would give the most prominent visual prove of
In this lab we are going to discovery how osmosis works using a semi-impermeable membrane a potato slice. Osmosis is known as the movement of water in and out of a cell. To understand how this works we must understand two terms. Hypotonic means the environment has less solutes compared to the inside of the cell. Hypertonic means that the environment has more solutes compared to the inside of the cell. With osmosis water will always move from hypotonic too hypertonic. So the question is will water move into the potato or out of the potato? Will these results change when placed in different morality of salt water? To calculate these results, we will measure the mass of potatoes cut into equal sizes then soak these potato slices in different morality of NaCl for thirty minutes and measure the mass change in each potato slice.