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In this coursework I am going to investigate the factor how different concentrations of sugar solutions will affect the rate of osmosis on a potato cylinder,

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Introduction

Introduction In this coursework I am going to investigate the factor how different concentrations of sugar solutions will affect the rate of osmosis on a potato cylinder, which will be no shorter than 5cm. When obtaining my results I will record the mass of the chip (cylinder) before I put it into the solution and the mass after the chip has been placed into the solution for a certain amount of time of 2 hours. I also plan to obtain 3 sets of to conclude an average from the results to put into a graph I am also going to apply this to the length of the potato chip. I will also take three readings for reliable and errorless results, and I will calculate the required averages to use in my graphed results in the analysis. The potato tissues, being surrounded by a weak solution, will be most likely to swell up and become turgid, taking in all the water it possibly can. Prediction I predict that the affect of changing the sugar solutions will affect the rate of osmosis i.e. The less concentrated the sugar solution is the more affect osmosis will have on the potato chip, meaning that the mass and the thickness of the chip will increase as a result. I am going to provide evidence to back up my prediction in my scientific theory. Scientific Theory Osmosis is the diffusion of water molecules from a domain of higher water concentration to a region of lower water concentration through a selectively permeable membrane. Plasmolysis is also involved in osmosis. Plasmolysis occurs when a plant cells membrane shrinks away from its cell wall. ...read more.

Middle

Final Length (cm) Change in Length (cm) 0.0 6cm 6cm 6cm 6.2 5.5 6.3 + 0.2 - 0.5 + 0.3 0.1 6cm 6cm 6cm 6.1 6 6.3 + 0.1 0 + 0.3 0.2 6cm 6cm 6cm 6.1 5.8 6.2 + 0.1 - 0.2 + 0.2 0.3 6cm 6cm 6cm 6 6 5.9 0 0 - 0.1 0.4 6cm 6cm 6cm 5.9 5.9 5.7 - 0.1 - 0.1 - 0.3 0.5 6cm 6cm 6cm 5.7 5.8 5.6 - 0.3 - 0.2 - 0.4 Concentration g/ dm3 Original Volume (cm3) Final Volume (cm3) Change in volume (cm3) 0.0 20cm3 20cm3 20cm3 18cm3 20cm3 18cm3 -2 0 -2 0.1 20cm3 20cm3 20cm3 16cm3 20cm3 16cm3 -4 0 -4 0.2 20cm3 20cm3 20cm3 19cm3 18cm3 20cm3 -1 -2 0 0.3 20cm3 20cm3 20cm3 19cm3 20cm3 20cm3 -1 0 0 0.4 20cm3 20cm3 20cm3 18.5cm3 20cm3 21cm3 -1.5 0 +1 0.5 20cm3 20cm3 20cm3 20cm3 20cm3 21cm3 0 0 +1 This preliminary experiment will help me to know what kind of results to expect in my next set of results for the other experiment. I decided to use the mass experiment to put into my original table of results. My reason for this is because I think that the mass experiment will provide reliable and errorless results that I can put into a graph. I have kept the apparatus, variables and safety precautions the same. However, I have varied the method according to the mass experiment, which is slightly different from the preliminary experiment. Method 1) Collect all apparatus 2) Peel the potatoes. 3) Use the cork borer to make 5 cylinders of potato 4) ...read more.

Conclusion

Although my results were reliable enough to draw a strong conclusion there was one error in my results, which I have clearly labelled in my graph. I have thought of the different ways this error could have occurred. They are as follows: - The potato chip may have been cut too short. To be precise it could have been cut a few millimetres too short. - The volume of the sucrose solution may not have been measured properly. - The potato chip may have been dropped into the test tube too hard, which may have caused some of the water to splash out. I think that my method was probably the best way of carrying out the experiment. If I did it the experiment again I would use a digital stopclock to give me more accuracy for the timing of the experiment. This would enable me to obtain better quality results, in which I could also draw a stronger and more confident conclusion from. The method gave me results that were reliable and accurate enough for me to rely on to give me sufficient information to draw my conclusion. I also had an amount of results that could give me the information to do so. I was able to count on my results because they were strong enough to give me an adequate quantity of data. There could be other ways to extend this investigation. I think that it would make the investigation more challenging if I investigated how the diameter of the potato chip is affected by different concentrations of sucrose solution. I could also investigate different solutions and materials other than potato; one of them being water, to see how different solutions with different amounts of water affect different factors of osmosis. Created by Aaron Miller Emmanuel Koduah ?? ?? ?? ?? ...read more.

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