Class 4

For class 4, we did an osmosis lab. My lab partner, Alex, and I first created six "cells" using dialysis tubing and different color solutions. The we massed the cells. Then we placed them each into separate cups of 50ml of distilled water. After 30 minutes we re massed the cells and calculated the percent mass change. The clear cell had a mass change of 8.219% and a molarity of 0.2. The purple cell had mass change of 20.988% and 0.8M. The yellow had a mass change of 21.053% and 0.6M. The red cell had a mass change of 27.161% and 1.0M. The blue cell had a mass change of 0% and 0.0M. The green had a mass change of 13.514% and 0.4M. From the percent mass change, we can infer the molarity of the solutions. Osmosis is the net movement of the solvent molecules through a permeable membrane into a region of a higher solute concentration. A hypotonic solution is a solution that has a lower concentration of solutes and higher amount of water. A hypertonic solution is a solution that has a higher concentration of solutes and lower amount of water. The solutions want to reach a isotonic state, or equal state. This means that the water will move from the hypotonic solution to the hypertonic solution to try and balance out the solutions. In the lab, the mass changes meant if the solutions were hypotonic or hypertonic. If the result of the lab meant that the mass of the "cell" decreased, then that means that the cell was hypotonic because water transferred out of the cell. If the cell gained mass, then the cell was originally hypertonic because water went into the cell. My lab partner and I did part 4 of the lab next, which was with the rehydration drinks. We made six cells using the dialysis tubing and orange Powerade. We then put the new "cells" into six different cups containing six different color solutions. We originally massed the cells before putting them into the cups. Then, during the evening, we came back and massed the cells again. Every cell decreased in size except the cell in the blue solution. This means that all the cells, except the one in the blue solution, were hypotonic in relation to the Powerade. The blue solution was hypertonic to the Powerade. In the next class we did the diffusion part of the lab.