Diffusion and Osmosis Labs: Part 2 and 3

In class 9/2/13, we did two labs. The first lab was Osmosis- Movement of Water High to Low. The objective of this lab was to find the molarities of the different solutions. In order to do so, we created six cells and filled each with 7 milliliters of different liquid substances in each cell. We massed each cell and then placed each cell into a cup filled with distilled water. We waited 30 minutes and re-massed them and calculated their percent change of their mass. We found that the blue liquid substance had the lowest Molarity because it was actually water. Through osmosis, the blue substance in the cell permeated through the cell because the blue substance had high concentration and permeated from the cell to get to the low concentration distilled water. On the other hand, the red liquid substance which had the highest Molarity increased in mass because the distilled water moved into the cell which contained lower concentration liquid.

 

 

In part 3, we cut a red potato into 24 pieces and massed 4 potatoes as a group. We placed each group of potatoes into a cup and added a different solution to each cup. Then we covered each cup with Parafilm. We came in 9 hour and re-massed the potatoes in each cup. Then calculated the percent change. We found that the result to be opposite from the previous experiment. The potatoes that were in the red solution had the lowest percent change and that the potatoes in the blue solution had the highest percent change. The potatoes in the blue solution(water) increased in mass because the potatoes absorbed the water since the potatoes has a low concentration. The potatoes in the red solution had the lowest percent change because both the potato and the solution had almost the same concentration.