Osmosis Lab Write Up
The function of this osmosis lab is to investigate the relationship between solute concentration and the movement of water through a selectively permeable membrane by the process of osmosis. The movement of water between the dialysis bags went through different concentrations of sucrose solution and distilled water. By increasing the molar concentration of sucrose solution in different percentages, small hints of more diffusion between the dialysis bags was made clear. In conclusion, our hypothesis about the increase in molar concentration of a sucrose solution leading to an increase in percentage change in dialysis bags was true.
After working on the osmosis lab, we tested the plasmolysis of an onion cell by demonstrating how separate substances emerge by placing an onion in water with three drops of 15% NaCL. Plasmolysis is the shrinking of the cytoplasm of a plant cell in response to the diffusion of water. As a result, the cellular membrane was exposed from the recession. By observing the small piece of the soaked onion, it led us to hypothesize how the onion cells lost water and diffused into the salt. After adding back fresh water, it revitalized the onion cells. One similarity between plasmolysis, the contraction of protoplasm due to the cell losing water, and osmosis, the equalizing of concentrations on each side of the membrane, was the loss of liquid to another side, involving the addition of water as an independent variable. The goal was to demonstrate how the movement of water through a selectively permeable membrane with the addition of increased amounts of sucrose solution affected the mass percentages of dialysis bags. The purpose was to investigate the relationship between solute concentration and the process of osmosis with the addition of independent and dependent variables.
What was the effect of increasing the molar concentration of sucrose solution on percentage change in dialysis bags?
If the molar concentration of sucrose solution was increased, then there would be an increase in the mass in dialysis bags.
The independent variable was the molar concentration of sucrose solution. The dependent variable was the mass in dialysis bags. The controlled variables were the room temperature, the pressure, the beakers of distilled water, the dialysis bags, and the 30 minutes that the dialysis bags soaked.
1. Six 30 cm strips of presoaked dialysis tubing
2. Six beakers full of distilled water
3. 20 mL of distilled water
4. 20 mL of 0.2 M sucrose
5. 20 mL of 0.4 M sucrose
6. 20 mL of 0.6 M sucrose
7. 20 mL of 0.8 M sucrose
8. 20 mL of 1.0 M sucrose
9. One electronic balance
10. Clean water
1. Obtain six 30 cm strips of presoaked dialysis tubing.
2. Fill six beakers full with distilled water.
3. Tie off one end of each piece...