Investigation Into Osmosis :: Papers

Investigation Into Osmosis Aim === The aim of this experiment is to compare the change of mass of potatoes when they are in a Starch and water solution. The reason the mass would changes is due to osmosis. Introduction ============ [IMAGE] Osmosis is the process of water passing from a region of high concentration of water, through a semi-permeable membrane to a region of low water concentration. Osmosis occurs when there is more water on one side of the cell than the other. In the example to the right the small blue particles represent water. There are more of the small blue particles on the left-hand side so the number of water molecules on each side would even out until the water cells are in equilibrium. The experiment we are doing is to see how much of the water has diffused and how much mass the potato lost or gained. Variables ========= I chose to investigate the mass of potato and volume of solution lost or gained when potato is put in water/ sucrose solution. The variables I didn't change were:  · Start volume of solution  · Start mass of potato  · Surface area of potato  · Amount of sunlight  · Length of time  · Type of potato  · Temperature The variables that I changed were:  · Concentration of sucrose/ water solution. Preliminary work ================ We did a preliminary experiment to check that the measurements and amount time would give us clear enough results. Method ====== We took three test tubes with 10ml solution in each. One with 0M sucrose One with 0.5M sucrose and the other with 1M sucrose, a test tube rack, three bungs and three pieces of potato. We weighed the three pieces of potato and cut them down to make them the same mass to make it a fair test. Then we made the water/ sucrose solution using these measurements: