How Osmosis Affects A Potato Chip Essay -- GCSE Biology Osmosis Course

How Osmosis Affects A Potato Aim: - To See How Osmosis Affects A Potato Preliminary work Prediction: -I predict that the weight of the potato in the sugar solution will decrease and the weight of water will increase. I predict that the weight of the potato in the sugar solution will decrease when it reaches 3:1 (salt: water). In put Variables: -Molarity -Size of potato -Mass of Water -Molarity of Sugar -Length of time in the solution -Temperature of water Out put variables: -Weight of potato Key variables: -Molarity of sugar. This is a key variable because it has the most effective outcome because osmosis only works when there are different molarities in and outside of the potato other wise the diffusion theory of osmosis wont work. We are going to keep a fair test by: - Keeping all the volume of water the same in each test tube - Keeping the starting weight of the potato the same to begin with - When removing the excess water of the potato make sure all excess water is removed but without squeezing any water out of the potato - Keeping the temperature of the water the same - Use the same type of potato (grown from the same potato) We will keep the experiment safe by making sure that all the test tube racks are in a suitable position so they wont easterly be knocked over. Preliminary results --------------------------------------------- Sugar Water Time left in 0.44g 0.44 Start 0.43g 0.44 5mins 0.42g 0.45 10mins 0.49g 0.46 15mins 0.38g 0.46 20mins --------------------------------------------- The table above shows the weight of the potato. Prediction I predict that the weight of the potato in the sugar solution will go down and the weight of the water will decrease because the water molecules in the sugar solution are small enough to diffuse through a semi-permeable membrane in the potato is the high concentration of water and water will only go through from a high concentration to a low concentration of water. Water goes into a potato sample because there is a higher concentration of water out side the potato than inside of the potato and water will go from a high concentration to a low concentration therefore the water will go into the potato and... ... to be sure to show a constant pattern. We didn't have any anomalous results maybe because we mad sure that we left each potato in the solution an equal amount of time. Also when we removed access water we were very careful not to squeeze any water out of the potato other wise it would of made it an unfair test. To improve reliability and accuracy next time in the prim nary plan I would make sure that my prediction was detailed so I would understand everything much clearer in order to get a better set of results. Also the preliminary experiment next time will be a lot more accurate in the way that we should take more care in time that the potato is left in the solution for how ever long of a time it should be left in. The main plan could be longer and in more detail so that it is more clear to read and understand. The amount of results that we got was just about enough to work out and see weather the prediction was correct. This means that next time we should do more sets of results to get a more accurate outcome. To help back up this experiment we could use more chats of graphs showing rate of osmosis in time and other ways of showing how osmosis affects a potato.