How is Osmosis Affected By the Concentration
PLANNING
Independent Variable
The independent variable in this experiment is the thing that I will be changing in the experiment. This is the range of concentrations that have been obtained by diluting the original 1M solution of Sucrose. This is therefore the only thing that is going to be altered as I am investigating how different percentage of water molecules affects the weight of the the potato thus the rate and direction of osmosis.
Dependant Variable
The dependant variable will be the mass of the potato as this is the variable I will be measuring. From this I can see the change in mass(g) and so work out the amount of water that has moved and the rate of the osmosis in a
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To makes sure that this does happen and that the controlled variables are controlled I will be doing a second test to ensure that the results are reliable.
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| |(Sample of Potato) Change in Length/mm |
CONCENTRATION / M |1 |2 |3 |mean | |0.0 |50 |52 |54 |52 | |0.2 |50
Figure 1: Percentage change in potato tuber mass vs. sucrose concentration. The percent change in mass decreased as the sucrose concentration increased. Relative osmotic concentration was measured as the percent change in mass of sucrose concentration over one hour.
Procedure: Variables: Controlled- water and size of potatoes. Manipulated variables- potatoes growth based on contents of solution.
Aim: To find the concentration of a potato cell cytoplasm compared to sucrose and salt. I mainly was looking to see how concentration of salt/sucrose affects the mass of the potato cores.
As the molarity of the sucrose solution increased, the mass of the potato still increased, but at a decreasing rate, until the potato was submerged in the 0.4 M solution, in which its mass did not change at all. Then, as the molarity was increased further, the change in the mass of the potato started decreasing at an increasing rate. This tells us that in the 0 M and 0.2 M solution, the water potential of the potato was less than that of the sucrose solution because water entered the potato. In the 0.4 M solution, or at about 0.32 as the best fit line would predict, the potato cells were at equilibrium with the solution since the mass did not change. In the 0.6 M, 0.8 M, and 1 M solutions, the potato’s mass decreased, so it must have had a lesser water potential than the
As the Concentration of the Sucrose Solution decreases, the more the potato’s mass increases. This is due to the solution being hypertonic. So, as the solute concentration gets lower, the potato’s water concentration will get higher, therefore more water particles from the solution will absorbed by the potato. Some changed very little in mass because the concentrations of the H2O molecules in the potato and outside the potato were equal. This equality in concentration is called Isotonic.
The graph above indicates that as the concentration of sucrose solution (%) is increased, the percentage change in mass decreases, thus it can be supposed that there is a negative correlation between the sucrose concentrations and the mass of potato cubes. It is also apparent from the graph above that an error has occurred during the 15% sucrose trial as it appears as an outlier also it can be estimated from the graph that approximately10% sucrose solution is the isotonic condition as there is no big change in mass.
I know that osmosis will occur in the vegetables, but I am not sure of
From the opening of Act 1 to the very end of the play Logos is the only thing that keeps twelve somewhat pessimistic men from sentencing a boy from the slum to death. If Number Eight in the jury had looked at the upbringing the defendant as all the others did, then a potentially innocent boy would have been put to death. One of the most powerful claims from the prosecution was that the murder weapon was a strange knife one which the defendant purchased. Such a claim was diffused with Logos by Number Eight when he was able to get “it in a little junk shop around the corner from the boy’s house”. In Act three it was the smallest detail that “she testified that in the midst of her tossing and turning she rolled over and casually looked out the window…she couldn’t have had time to put on her glasses…maybe she honestly thought she saw the boy kill his father. I say that she saw only a blur.” which was able to convince the entire jury of the reasonable doubt the needed to find the kid not guilty.
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
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
Within every cell, a movement of a solvent occurs through a semipermeable membrane to equalize the concentration of solute on both sides of the membrane. The diffusion of water across the cell’s membrane down to its concentration gradient is called osmosis. In this case, the concentration gradient is the difference of density between one side of the cell membrane to the other. Since the cell’s membrane is permeable, particles can flow freely in and out of the cell, but the net flow will be strong in the direction of lower concentration until the system has reached a stage of equilibrium, the point at which both sides of the membrane are equal. In the
Using different sizes of potato could show us whether the concentration of enzyme affect the rate of reaction. However, this would not be a practical independent variable as the S.A to volume ratio would not be proportional and the size of the potato to get significant results would be very hard to change. It would be very hard to cut the potato tubers to exact measurements and that could lead to the results becoming inaccurate. An option could be to cut the potato tube into small 1 cm bits and pile then up on top of each other in the test tube, but this again would prove to be impractical as then not all of the surface area of the potato would be exposed to the substrate and this would make my results unreliable. It may also prove to be impractical as having the tuber bits piled on top of each
The purpose of methodology is to maintain the most accurate results by conserving the temperatures of each sample of potato. By wrapping the potatoes in tin foil, it not only maintains the heat of each, but it also allows them to have close to almost the same temperature with each other when they are trapped with the same heat. This makes sure that the hot potatoes do lose their heat and that the cold potatoes remain cold. Maintaining the same temperature for each potato prevents the results of the trials for the same potato from being different from one another. The control group consists of having the same type of potato, washing all the potatoes in the same water to get rid of grime, having about the same sized potato pieces, using 150 mL
Small slices of potato are placed in six concentrations of sucrose: 0.0 M, 0.1 M, 0.2 M, 0.3 M, 0.4 M, and 0.5 M. The initial mass of potato is noted before being placed in the solution. The potato remained in the solution for one hour then the potato was removed from the solution and dried off before the final mass was noted. The null hypothesis is that the solutions of different molarities of sucrose will not affect the
How do different concentrations of sucrose solutions (0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M) affect the mass of potato cores when in sucrose solution?