Essay on Osmosis lab

719 Words Oct 3rd, 2014 3 Pages
Abstract

The objective of this experiment was to test the effect of a specialized type of diffusion called osmosis, “which involves in selective transport of water molecules across a selectively permeable membrane” (Lab Manual 2nd edition). It was hypothesized that osmosis will occur when there is an uneven distribution of solute in a solvent. The more abundant the solute is in solvent, the higher the rate of osmosis through the diffusion gradient forming a hypertonic or hypotonic solution. Solvent with equal or no solute forms an isotonic solution. Throughout this lab, data was collected and compiled to analyze these effects across selectively permeable membranes. The results indicated that the water molecules indeed move from
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The second bag filled with distilled water, submerged in a beaker with water, had no significant difference in weight as time progressed indicating the solution was isotonic. The third bag filled with 40% maltose solution, submerged in a beaker filled with distilled water, expended insignificantly, indicating that water molecules from the beaker were able to pass through the bag filling it to capacity, but sugar molecules were unable to pass through the bag. Finally the fourth bag, which had 40% maltose solution in bag as well as the beaker, also did not have any significant changes, once again indicating the solution was isotonic. The last experiment pertaining to this activity was done to test for sugar in test tubes using Benedict’s solution. All three test tubes (1,3,4) showed a change in color to orange, except for the second test tube, which turned light blue. These results indicated that test tube 1,3,4 had sugar molecules present, except for the 2nd one, which had only water. Even though the first tube only had water, it still turned orange indicating that sugar molecules somehow got into the solution. Based on the raw data provided above for the dialysis bag experiment, the results confirmed that permeability is selective, where water molecules easily passed through the bag, but maltose molecules did not. It was evident that these sugar molecules were too big to pass through this selectively permeable membrane.

The following activity was performed to

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