Osmosis and Diffusion Lab

        The purpose of this lab was to observe the rate of osmosis and diffusion, as well as the effect of molecular size of the particles on this rate. Part I of the lab was a demonstration of osmosis and diffusion, that dealt with raisins in different liquid environments, each with a different concentration of sugar. Part IV of the lab was using the same idea as the demonstration, by putting objects in different concentrations of a substance; in this case elodea leaves in salt water. In both cases, the objects in a greater concentration of the substance were stripped of their water. However, where there was a little or no concentration of sugar or salt, the objects did not lose their water, and in the case of the raisin, became saturated with excess water. Part II of the lab dealt with the rate of osmosis, and how molecular size was a factor on it. The purpose was to see how easily molecules of smaller diameter, which were starch molecules, would pass through an artificial membrane, as opposed to how difficult it would be to pass through in the case of larger molecules, which were IKI molecules. Results were that the smaller substance passed though the membrane easily and rather quickly, and the larger substance did not penetrate the membrane whatsoever. Part III of the lab was to view the effect of molecular size on the rate of diffusion. Two substances, both being of different molecular size were placed in the same environment. Results were that the substance with the smaller molecules, diffused farther away from where it was placed than did the substance of greater molecular size in the same amount of time.

The title of this lab is 'Osmosis and Diffusion.' Both these terms deal with the transfer of...