Determining the Rate of Osmosis Through a Semi-Permeable Membrane
Schneider, Justin* Sec 16 and Thomas Hudson
Water is the principle solvent in cells. There are three conditions that a cell may be subjected to in the cells physical environment. The cells may be isotonic, hypotonic, and hypertonic. Isotonic is when the cell and is environment have equal concentrations of solutes. Therefore cells in an isotonic solution do not experience osmosis. When the cell is hypotonic it has a lower concentration of solutes so water will move out of the cell. When the cell is hypertonic, it will have a higher concentration of solutes and water will move into the cell to attempt to reach an isotonic state. The primary purpose of …show more content…
Once the bags were placed into each solution, a timer was started. At 15 minute intervals each one was taken out of the solution, they were then dried off and the weight was recorded. This was so an increase or decrease in weight could easily be seen. Each bag was taken out, dried and was weighed at 15 minutes, 30 minutes, 45 minutes, and at 60 minutes to conclude the experiment.
Both of the bags C and D were hypertonic to their surrounding environment. Because the sugar (Solute) couldn’t pass through the membrane it was only water going in or going out of the bags in the solution, which is the case for osmosis (Raven, et al. 2011.)
Bag A reduced in weight by 2.8 (g) in 60 minutes. The largest reductions in weight occurred in the first 30 minutes. In the 30 to 45 minute range it still dropped 0.6 (g), and another 0.4 in the 45 to 60 minute time period. Bag B did reduce in weight, which was unexpected because it was supposed to be isotonic with its