Potato and Osmosis Experiment
Potato and Osmosis Investigation Skill Area P: Planning Aim: To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and a potato chip of a given size. Hypothesis: Osmosis is defined as the net movement of water or any other solution¡|s molecules from a region in which they are highly concentrated to a region in which they are less concentrated. ... For this particular investigation I think that the lower the concentration of the sugar solution in the test tube the larger the mass of the potato will be. ... In the potato chip. ... „Y At point A the graph tells the viewer that no osmosis has occurred, suggesting that the concentration of water inside the cell is equal to the solution outside. ... Further information on potato plant cells: Plant cells always have a strong cell wall surrounding them. When they take up water by osmosis they start to swell, but the cell wall prevents them from bursting. ... This liquid or hydrostatic pressure works against osmosis. ... When plant cells are placed in concentrated sugar solutions they lose water by osmosis and they become "flaccid. ... The contents of the potato cells shrinks and pulls away from the cell wall. ... Variables: To create a fair test certain aspects of the experiment will have to be kept the same whilst one key variable is changed. ... For instance if one of the potato chips was 1cm longer the surface area of the chip would be larger and there would therefore be more space for osmosis to occur. ... „X For the purpose of my experiment I am going to do all the experiments at room temperature. „X To keep the water potential of the potato initially will be kept the same by using the same type of potato, which have been treated in the same way, e. ... „X The mass of the potato is a dependent variable, and this means that it will be measured throughout the experiment. ... The potato chip will be measured before it is put in the solution, and after. This will allow us to see whether osmosis has taken place, and to what extent. „X The volume of the solution that the potato chips are kept in must be fair. The must be totally covered in the solution, and the amount of solution will be kept the same because all the potato chips are the same size. „X I am also going to use the same balance to weigh my potato chips. ... TABLE SHOWING THE DIFFERENT VARIABLES THAT WILL BE CONSIDERED DURING THE EXPERIMENT Variables Non-Variables Solution concentration Surface area Solution volume Duration of experiment Temperature Solution Weighing scales Conditions Preliminary Results Concentration of solution Mass Before Mass After % Change in Mass 0. ... Sections of potato will be cut using a scalpel and will be measured using a ruler. This part of the preparation must be done very accurately as a change in the surface area may allow more or less osmosis to occur. ... The potato pieces will then be placed in the different test tubes and then left for 30 minutes.