The aim of my experiment is to find the salt concentration in a potato tuber.
             I predict that osmosis will occur between the potato tubers and the solutions. I think that the potato tubers in distilled water will increase in length and mass while the potato tubers in the 100% salt solution will decrease in mass and length. Somewhere between these two solutions is the salt concentration of a potato tuber.
             There are several reasons that I have made my prediction above. I have knowledge about osmosis from previous experiments and I know that it is a special case of diffusion. Water molecules pass through a partially permeable membrane. In this experiment the partially permeable membrane will be the potato tuber cell membrane and I will be testing for the concentration of salt in the potato tubers. I know that when osmosis occurs water molecules travel from a high concentration to a lower concentration. In my experiment the concentration of the solution will be varied so when the concentration of the potato tubers are higher than that of the solution, the potato tubers will become smaller and lighter because the will have lost water.
             Osmosis is a special case of diffusion in which water molecules move from an area of high water concentration to an area of lower water concentration through a partially permeable membrane. A partially permeable membrane is porous but allows water to pass through it more rapidly than the dissolved substance because the water molecules are much smaller. A dilute solution contains, in effect, more water molecules than a concentrated solution. This is because in a concentrated solution the salt dissolves in water and the salt molecules attract some of the water molecules and stop them moving freely. This means that there are more free water molecules in the dilute solution. There is a diffusion gradient that favours the passage of water from the dilute to the concentrated solution.
             The water potential o...