abstract water potential

The purpose of the Osmosis and Diffusion lab was to properly demonstrate osmosis, diffusion and water potential.
In part 1a dialysis bags were filled with a solution consisting of 15% glucose, 1% starch and 74% distilled water and placed into a 125 ml beaker containing water, potassium and iodine for about 20-30 minutes. The dialysis bags were tested before and after being submerged for the presence of glucose. The gathered information leads to the conclusion that glucose was diffusing through the dialysis bag and into the solution of water, potassium and iodine. This successfully demonstrates diffusion.
In part 1b, dialysis bags were filled with sucrose solutions ranging from 0.2 to 1.0 M by increments of 0.2 and one with distilled water. Each bag was massed and then submerged in a beaker of distilled water for 30 minutes. After the 30 minutes, the bags were removed and massed. The data shows that the dialysis bags with sucrose increased in mass. The distilled water did not, however, increase.
In part 1c, potato cores were massed. The potato cores were placed in sets of four to six 250ml beakers of sucrose solution. The sucrose solutions varied from 0.2 to 1.0M solution by 0.2 increments and a control group of distilled water. They were massed again after 24 hours. The data showed that in the solutions 0.0 -0.2 M had an increase in mass. In the beakers 0.4 through 1.0M, the core decreased in mass. It is predicted that the potato’s water potential is the same as that of a solution 0.3M of sucrose.
In part 1d, the water potential of the potato was calculated. It was found to be decreasing as molarity increased.
In part 1e, a small piece of the epidermis of an onion was placed in a microscope. It was observed to have dim yellow scales, interlocked and somewhat uniform in shape. After being observed, salt water was added to the edge of the sample. The result was observed to be comprised of smaller scales. After that, the onion was observed with distilled water added. The scales increased in size, close to their previous size.