Lab: Diffusion and Osmosis

Lab: Diffusion and Osmosis

In the Diffusion and Osmosis lab, we got a better understanding of osmosis. We used dialysis tubing to find the relationship between solute concentration and the movement of water through a selectively permeable membrane. Before conducting this experiment, I made a hypothesis of, if the amount of sucrose increases inside a semipermeable membrane placed in distilled water, the solution will be hypotonic and the water will go into the sucrose, and add more mass, because the solution has less solute. First in the experiment, we filled presoaked dialysis tubing with 15-25 mL of 0.8 M and 1.0 M of sucrose. After filling the bags, we found the mass of each bag in grams. Next, we placed each bag in a cup filled with distilled water and let them sit in the water for 30 minutes. After the 30 minutes were complete, we removed the bags and measured the mass again of each bag. The class compared their data with other students and we concluded that the more sucrose that was contained in a bag had a higher percent change in mass after being placed in the water. This shows that my conclusion is correct, and that since the sucrose was hypotonic, meaning the solute concentration in the environment is lower than in the cell, the water would move into the so called “cell” or semipermeable membrane. Even though my hypothesis was correct according to our data, there were sources of error, and without them, our data could have been different. A main source of error in the lab was the scale, and how it only goes to one decimal point. This makes our data less accurate. We could correct this error by getting a scale that has more than one decimal point. The water moving into the bag in this lab shows osmosis. Osmosis is part of cell transport. Cells preform transport in order to get things that are needed (water, sugar, amino acids) in and to remove waste. Osmosis takes place when a cell does or doesn’t have enough water compared to its environment and happens...