Method: The apparatus I used included a ruler, scalpel, core borer, marker, distilled water, sucrose solutions, measuring cylinder and some beakers. Firstly I used my marker and labelled each of the beakers (distilled water, 0.1 sucrose, 0.2 sucrose, 0.3 sucrose, 0.4 sucrose and 0.5 sucrose). Then, using the measuring cylinder, I carefully measured out 20ml of each solution. Next, using the core borer I cut out 30 pieces of potato and using the ruler and scalpel, I cut out potatoes that were 2cm in length. I put five of the 2cm potato pieces in each beaker. They were then left in the beakers for approximately 24 hours allowing the process of osmosis to take place. After the 24-hour period, I took a paper towel out and placed the potato pieces on it in order for them to dry. By going from beaker to beaker, I measured the length of the potato and compared it to the original 2cm length. Whilst doing this I plotted the data/information in a table. To ensure that my experiment was a fair test I ensured that the length of each potato chip was 2cm exactly. I also ensured that there were five pieces of potato put in each beaker and that there was 20ml of each solution. The test wasn’t repeated and to speed the process up I actually put all five pieces in each beaker at the same time. I used the Internet as a source of information in order to fully describe the osmosis theory.
Results:
Length Of Potato Chip Against Solution
Conclusion:
My results tell me that the more dilute the solution, the more length gained by the potato and in doing so it confirms my initial prediction. As an example, 0.5 sucrose allowed the potato to decrease in length by 0.06 cm whereas distilled water allowed the potato to increase in length by 0.32 cm. The osmosis theory stated that water would move from a high water concentration to a low water concentration using a semi-permeable membrane in order to do so. In this case the partially permeable membrane would be the potato chip. My results told me that if there were less water outside, the water would make its way into the chip. 0.5 Sucrose was the most concentrated solution out of the ones I used and distilled water was the most dilute. The dilute solution allowed the water to go through the semi permeable membrane whereas the concentrated solutions allowed the little water in them to go towards the sucrose as opposed to going towards the chip. My results suggest to me exactly what I thought they would in my prediction, which was that the length of potato would increase in a dilute solution and decrease in a concentrated solution.
Evaluation: I thought that the experiment was very successful as I received a large quantity of fairly accurate results. From these results I was able to draw up a somewhat informative graph. I think using five potato chips per beaker was enough and I also ensured that my experiment was conducted using a fair test so I cannot explain the anomalous result that I got. My results support my conclusion as well as my prediction and the diluted solutions increased just as I said they would. I could have improved and extended my investigation by using more potato chips. I used five per solution and had I used more my results would have been more accurate. My method was slightly wrong in a way because I may have checked thoroughly that the length of each chip was exactly 2cm, I never checked to see the mass. I could also have extended my investigation by noticing the mass change as well as investigating the change of length.
Dipan Vadgama 10DH