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Introduction

In this investigation I am going to find out how a chip is affected by the concentration of the salt water, the length or width of the chip or the length of time the chip is in the solution for. Osmosis Osmosis is the movement of water through a selectively permeable membrane separating solutions of different concentrations. Water passes by diffusion from a weak solution (high water concentration) to a strong solution (low water concentration) until the two concentrations are equal. The selectively permeable membrane allows diffusion of water but not of the solute. The level of liquid in the tube of sugar solution will eventually rise until the flow of water from the tube of sugar solution, under the influence of hydrostatic pressure, equals the flow of water into the tube. The hydrostatic pressure establishing this equality of flow is called osmotic pressure. A variety of physical and chemical principles are involved in the phenomenon of osmosis in animals and plants. Osmoregulation Excessive flow of water into a cell by osmosis can burst the cell. Cells protect against this using processes of osmoregulation. If external pressure is applied to the stronger solution, osmosis is arrested. By this mechanism plant cells can osmoregulate, since the cell wall of a fully turgid cell exerts pressure on the solution within the cell. Animal cells such as the red blood cell cannot osmoregulate in this way since they have no cell wall. Instead, the kidneys maintain the correct concentration of plasma. Diffusion Diffusion is a spontaneous and random movement of particles in a fluid from a region in which they are at a high concentration to region of lower concentration, until a uniform concentration is achieved throughout. ...read more.

Middle

Measure out 100 ml of water and then add none of the table salt, which will create 0% salt solution. 6) Measure out 95 ml of water and now add 5 ml of salt, this will create 5 % salt solution. 7) To create 10 % salt solution measure out 90 ml of water then add 10 ml of table salt. 8) To create 15% salt solution measure out 85 ml of water and then add 15 ml of table salt. 9) Then finally to create 20 % salt solution measure out 80 ml of water and then add 20 ml of table salt. Method Once you have set up the apparatus as shown before, and created the concentrations. Take five core samples using the 11 ml borer. Once you have completed that, remember to cut each sample to 3 cm, so that each of the samples are the same size to make it a fair test. Weigh the mass of each core sample and designate the core sample to a concentration and record the mass before. After you have done that place each core sample into its designated concentration at the same time and start the stopwatch. Then stir the solution with the sample in it 5 times using a spatula, and then leave it for until the stopwatch reaches ten minutes. Once it reaches ten minutes stop the stopwatch and takes the entire sample out of the solution and places them outside the designated beaker to prevent concentration. DO NOT TOUCH THE CONTROL SAMPLE WITH ANY OF THE EQUIPMENT USED FOR THE SAMPLE IN THE SALINE SOLUTION as this prevents contamination of the control sample. ...read more.

Conclusion

Looking at my graph and its line of best fit, you can see that there are a couple of points that don't really fit the pattern. However they all follow the trend of the other points, and it doesn't really affect the overall pattern or correlation. I believe that this method was reasonably secure, and that if performed properly there would be no major errors. However, the method was very simple and primitive, yet affective. As this is what would happen in reality. For instance, if you are making chips and you put the potatoes in a saline solution and they decrease in mass it might not be as scientific but the results are just as valid, because it can be conveyed to a human problem easier. The method would have been improved and more secure if I could have controlled such factors as, the length of time the sample is in the concentrate. I had great difficulty in this investigation is removing all of the samples from the different saline solution at the same time without contaminating the control sample. I believe that I have enough reliable results to draw a valid scientific conclusion. However, I don't have enough results to come to a conclusion concerning my prediction involving a concentrate of saline solution that a potato sample won't decrease in mass. I could have developed this investigation by testing a greater variety of concentrates, including 1% saline concentration to prove or disprove my hypothesis concerning a concentrate of saline solution that a potato sample won't decrease in mass. This investigation is useful for chip shop that prepares the chip hours before frying them. As it allows them to do so without the mass and size of the chips decreasing. Olivia Blain 11s ...read more.

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