I am going to investigate the relationship between Osmosis and concentration of sucrose solution.
In this experiment I will test if the concentration of the solution could affect osmosis because a lower molar concentration would cause the cell to increase in mass whereas a higher molar concentration solution would cause the cell to lose mass. I have chosen to use distilled water, .2Moles, .4Moles .6Moles, .8Moles and 1Moles because it gives a wide range and can be easily repeated, Molars(M) is the ratio of sugar compared to the water the higher the number the higher the concentration of sugar there is.
I predict as the sucrose solution gets more concentrated than the point of equilibrium the potato will lose mass, this is because the sucrose can’t get through the semi permeable membrane so water moves out of the cell causing to try and reach the point of equilibrium so decreases in mass. When the sucrose solution is less concentrated than the point of equilibrium the sucrose inside the cell can’t get trough the semi permeable membrane so water outside the cell moves in causing the cell to gain mass I think the molarity of the potato is about .4M.
I will make my potato sample by using a borer each will be a 1cm long to get accurate results using the scalpel on the chopping board, then place each in a boiler tube with 25ml of sucrose solution and I will record the mass of the potato using an electronic balance to improve accuracy we use it to 2dp to give accurate results before and after the 25 minute time period, and also record the change in mass.
From the table we can see that the molarity of the potato is between 0M and 0.2M At 0m the potato gained mass, at .2M the potato loses a slight amount of mass, .4M more mass is lost at .6M the rate at which mass is lost decreases then changes to the same rate at .8M which it was between .2and .4 then at 1M the potato loses mass but loses less than .8 I believe .6 and 1 could be anomalies. Mass is gained at 0M because the inside of the potato has a lower water potential then outside so water moves in to reach equilibrium the point where molecules are equal on both sides of the cell whereas at higher molarities there is less water potential inside the potato so water moves out of the cell to reach equilibrium. From the graph I believe the molarity of the potato is .07M because this is where the there would be no change in mass so equilibrium would have been reached.
