Determining the Rate of Osmosis Through a Semi-Permeable Membrane

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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
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Bag D did increase in weight but started to level out at the 30 minute interval. The total weight increase for bag D was 1.1 (g).
Figure 1. Changes in Weight of Dialysis Bags

Bags A, B, C, and D were all filled with 10 ml of sucrose solutions of 1%, 1%, 10%, and 25%. Once the bags were in the solutions of sucrose a timer was started. At 15 minute intervals each of the bags were taken out of the solutions, dried off and the weight was recorded. Bag A was placed in a container with a 25% sucrose solution. As the graph shows it reduced in weight meaning it expelled water trying to reach an isotonic state. Bags B, C, and D were placed in a 1% sucrose solution. Bag B was supposed to be isotonic with its environment, but as the graph showed reduced in weight slightly. Bag C had 10% sucrose solution, so it was hypertonic and should have increased in weight, but a leak was found in the bag resulting in a loss of weight. Bag D had a 25% sucrose solution and did increase in weight, but not as much as expected. Regardless it proved to be hypertonic. When bag D was tied there was not much extra room for the water to fill, therefore limiting the amount of allowed growth.
Even though the relationship between bag B and its solution was supposed to be isotonic it would have been interesting to see how far off the solution really was. The result that was found for bag B was a decrease of point seven (g). Bag A was still decreasing in weight by

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