Objective Determine the relationship between concentration of solution and osmosis Protocol Materials: six 30 ml dialysis tubes, clamps, tube holders, 250 ml beakers, distilled water, sucrose in 0. 2 M, 0. 4 M, 0. 6 M, 0. 8 M, 1. 0 M concentrations, electronic balance Six 30 ml dialysis tubes were obtained.
The bottoms of the bags were clamped to create bags. Twenty-five ml of each of the following were added to the separate bags: distilled water, 0. 2 M sucrose, 0. 4 sucrose, 0.
6 M sucrose, 0. 8 M sucrose, 1. 0 M sucrose. The open ends of the bags were clamped, leaving enough space to keep from pressurizing the bags. The bags were dried and their mass was recorded. Six 250 ml beakers were filled 2/3 full with distilled water.
Each of the six bags was immersed in one of the beaker for 20 minutes. Afterward, the bags were removed, dried, and their masses were measured again. Results Contents in dialysis bag Initial Mass (grams) Final Mass (grams) mass difference (grams) % Change in Mass Distilled Waster 33. 44 33. 54 0.
1 0. 294% 0. 2 M sucrose 32. 57 36. 66 4. 09 11.
2% 0. 4 M sucrose 36. 16 38. 00 1. 84 4. 84% 0.
6 M sucrose 37. 53 40. 41 2. 88 7. 12% 0.
8 M sucrose 38. 38 41. 07 2. 69 6. 55% 1. 0 M sucrose 32.
The Essay on Mass Determination
Objective: The purpose of this experiment is to see the difference of precision of different balances. When doing experiments we determine the mass my measuring the sample with a balance. There are many kinds of balances that measure to different precisions. This experiment shows the different results that two balances can give. Summary of Procedures Determine the mass with the triple beam scale ...
09 32. 97. 88 2. 67% Class average of percent mass difference Bag contents Group 1 Group 2 Group 3 Group 4 Group 5 Total Class average Distilled water. 98 2.
1 8. 17 0. 294 1. 35 12. 9 2. 58 0.
2 M 4. 07 6. 9 3. 88 11. 2 3. 7 29.
75 5. 95 0. 4 M 6. 80 8. 2 2. 78 4.
84 6. 56 29. 18 5. 84 0. 6 M 8. 74 9.
3 8. 76 7. 23 7. 94 41. 97 8. 39 0.
8 M 11. 53 13. 98 11. 43 6. 55 10. 1 53.
59 11. 92 1. 0 M 11. 91 16. 0 13. 39 2.
67 7. 33 51. 3 10. 26 Discussion 1.
The water flows from the less concentrated solution to that of a greater concentration. 2. Because of the property of osmosis mentioned above, the first two bags, containing distilled water and 0. 2 M solution, would decrease in mass, the mass of the 0. 4 M solution should remain about the same, and the mass of the remaining bags should increase. 3.
Each bag might contain slightly different amounts of solution, each bag might not be uniformly dried, and some of the bags were sealed with clips, while others were sealed with ties. As long as these differences remain the same for each bag, the percentage of mass difference is more accurate. The results for our group were not the anticipated results because the volume of solution added to each bag was not uniform and the bags were not uniformly dried before weighing.
