Osmosis Lab Report Essay
Natasha Tenen Lab: Thursday (3-6 pm) OSMOSIS LAB REPORT INTRODUCTION Osmosis is a special type of diffusion where water molecules move down a concentration gradient across a cell membrane. The solute (dissolved substance) concentration affects the rate of osmosis causing it either to speed the process up or slow it down. Based on this, how does different concentrations of sucrose affect the rate of osmosis? If sucrose concentration increases in the selectivity-permeable baggies, then the rate of osmosis will increase. MATERIALS AND METHODS
The start of the experiment consisted of filling up four beakers with de-ionized water to 150 ml.
After the beakers were filled to the appropriate amounts they were then labeled with the different sugar concentrations (0m, 0. 25m, 0. 5m, and 0. 75 m). Each group member had to obtain one dialysis tube bag from the distilled water and tightly tie one end with string. After one side of the bag was tied, each group member had to fill their tubes up half way with one of the four types of sucrose solutions (each member used a different concentration of solution).
After the tube was filled up halfway, each member then tied up the open ends of the bags tightly with string. Because the bags need room to swell, they were not tied right next to the sugar solution. After each bag was tightly secured each bag was rinsed with de-ionized water to wash away any spilled sugar solution. Then each bag was weighed on a scale and the members recorded the results within the group. Once all four bags were weighed, each bag was placed inside the water with the appropriate labeled beaker at the same exact time.
Once the bags were in the water, the members had to wait thirty-five minutes for osmosis to take action. After thirty-five minutes, the bags were taken out of the water and were dried. Once the bags were dried, each bag was weighed and the members recorded the results. The last step was dividing the final weight by the initial weight and multiplying by one hundred for each of the four bags. RESULTS Each group received similar but different weight gain results. Group 1 received 107% for 0. m, 109% for 0. 25m, 112% for 0. 5m, and 126% for 0. 75m. Group 2 received 100% for 0. 0m, 107% for 0. 25m, 116% for 0. 5m, and 117% for 0. 75m. Group 3 received 100% for 0. 0m, 106% for 0. 25m, 114% for 0. 5 m, and 117% for 0. 75m. Group 4 received 100% for 0. 0m, 106% for 0. 25m, 113% for 0. 5m, and 116% for 0. 75m. Group 5 received 98% for 0. 0m, 105% for 0. 25m, 110% for 0. 5m, and 115% for 0. 75m. Group 6 received 104% for 0. 0m, 108% for 0. 25m, 111% for 0. 5m, and 104% for 0. 75m.
The trend line that occurred for the rate of osmosis was an upward increase as the solute concentration increased. DISCUSSION The class data that was received supported the group members’ hypothesis that the rate of osmosis will increase if the sucrose concentration increases as well. The trend line that was received from the data also supported the hypothesis because it increased as the sucrose concentration increased. The initial weight gain percents were all different because all of the groups’ sugar concentrations were not completely identical.
The method used wasn’t entirely accurate because there could’ve been some flaws such as some bags weren’t secured enough and might have leaked sucrose into the de-ionized water causing the results to be different. The bags might have not been washed thoroughly which could have ultimately allowed sucrose into the de-ionized water. The results could have been more accurate if the baggies were left in the beakers for a longer amount of time then thirty-five minutes. Nonetheless, the rate of osmosis was surely displayed within this experiment.