Determination of the water Potential of cells of bulky tissues by a weighing method
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Introduction
Determination of the water Potential of cells of bulky tissues by a weighing method Aim The aim of this experiment is too find the water potential of the potato cells by a weighing method. Prediction I predict that as the concentration of sugar solution sucrose is increased, the mass of the potato will go down more and more thus the water potential decreasing as well. This is because the water molecules move to where there is a region of low water potential from a region of high water potential. So when the solution is one molar of sucrose there is a very low water potential because there is no water in it. ...read more.
Middle
5. Now I could start adding the different molar of sucrose to the test tubes and I labelled each one so I know which test tube had which molarity in. 6. I left the solutions for a good hour and then I weighed out the potato again and recorded it down on paper. I did this with all the pieces of potato and then found out the percentage change in mass with each one. Concentration of sucrose Weight before (g) Weight after (g) Change in mass (g) % change in mass 1 Molar 1.21 0.89 0.32 3.9 0.9 Molar 1.23 0.92 0.31 3.8 0.8 Molar 1.1 0.81 0.29 3.2 0.7 Molar 1.15 0.89 0.26 3 0.6 Molar 1.13 0.91 0.22 2.5 0.5 Molar ...read more.
Conclusion
I know this because in my table it shows that when the concentration of sucrose was decreased the change in mass also decreased until the potato ended up gaining weight which at this point meant that the solution of water and sucrose had a greater water potential than the potato. Evaluation My experiment was fairly accurate and my results seem to be fairly normal. If I was doing the experiment again and had more time I might of done each concentration of sucrose twice or a few times and I would of taken an average of these results. This would be more accurate because something could go wrong if I was only doing each one once like you might use the wrong concentration for one of them. I think I left my experiment long enough for affective osmosis too take place. ...read more.
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