How Long Do Solid Diffuse Faster Than Solids

The results of the diffusion experiment showed that the solid diffused farther and more quickly in the solid medium than it did in the liquid medium (fig. 1). This did not coincide with the original hypothesis that the solid would diffuse more rapidly in the liquid medium. However, I would still maintain that a solid will diffuse faster in a liquid because it is already known that liquids diffuse faster than solids because of their composition. Also, the purple color of the potassium permanganate spread throughout the entire test tube of water, while the methylene blue crystal did not diffuse throughout the entire petri dish of agar (fig. 2). Both substances reached a plateau and stopped diffusing after a certain number of minutes, which

5), and confirmed that all of the liquid substances did pass through the filter, while the only solid substance that was used did not pass through. The filtrate at the end of the experiment was a diluted blue color, showing that water and copper sulfate passed through, and the test for starch was positive meaning that starch was able to pass through as well (fig. 6). The powdered wood charcoal was the only solid material and was the only one to remain in the filter after the experiment was complete. This is another example of a selectively permeable membrane since the larger, solid particles were not able to pass through, but the smaller, liquid particles were. The dialysis experiment did not concur with the original hypothesis that all of the substances would be able to pass through the dialysis tubing into the surrounding water in the beaker. Sodium chloride and sugar did pass through the membrane while starch, was not able to pass through (fig. 7). These results show that sodium chloride and glucose (sugar) are small enough molecules to permeate the membrane, but starch is a much larger molecule and therefore was not able to get through. This is understandable because starch has a much higher molecular weight than the other two