Methods, and materials
To observe the effect of concentration on the rate of osmosis four solutions were placed into four beakers containing tap water. Solution 1 was tap water. Solution 2 was 20% sucrose, a disaccharide composed of glucose and fructose. Solution 3 was 40% sucrose. Solution 4 was 60% sucrose.
The dialysis bags created artificial cells to demonstrate osmosis. The dialysis tubing was clamped at the bottom then clamped at the top after pouring 10 mL of each solution into the correctly labeled solution and removing excess air. This ensured malleability. An initial measurement of weight was made. Each beaker was then filled with water at a level high enough to envelop the bags.
To reduce error in weighing the solutions exterior moisture on the bag was blotted prior to calculation. Solutions 1-4 were placed in their appropriate beaker simultaneously. For sixty minutes the bags were weighed at ten-minute intervals after being blotted and the measurement was recorded in Table 2.
At the conclusion of the experiment the solutions and the contents of the dialysis bags were exposed of in the sink.
The cumulative change (g) in weight quantitatively measured how much the weight changed since the last ten-minute interval. The corrected cumulative change in weight (g) subtracted the difference of water's cumulative change in weight at the same interval. Solutions 2-4 are all hypotonic because sucrose has a higher concentration than water so water moves into the cell. Water, solution 1, represented an isotonic solution or a normal state. In an isotonic solution the solute is equally concentration so water moves both in and out of the cell. This allows a more accurate evaluation of the effect of concentration on the rate of osmosis. Rate of osmosis was found by graphing a best-fit line of corrected...