Biology
20 November 2013
Osmosis Lab
Problem: What’s the order of the concentration for each solution and how does it affect the movement of water?
Hypothesis:
Experimenter thinks the order of the solutions according to their concentration is D,A,E,C,B, from smallest. And the water will pass through semipermeable tubing bag from low to high concentration to thin the concentration inside the bag. Osmosis is a diffusion of water particles and is one of the passive transport that the molecules try to reach equilibrium is reached to the concentration. Introduction:
In this experiment, the experimenter tried to organize the order of 5 unknown solutions by using dialysis tubing lab. The 5 solutions were put into each tubing bag that were all tied up and placed into each beaker of water and waited to look for the change in masses of each bag. The type of solution that were put in the tubing bag are the independent variables and mass changes that occurred are the dependent variables. All the groups are experimental group and none of them is a control group.
Materials:
• five sucrose solutions of unknown concentration, labeled solutions A, B, C, D, and E.
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• dialysis tubing
• plastic cups
• plastic syringes
• distilled water
Procedure:
1. 5 strips of dialysis tubing in a beaker of water to soak to soften the Dialysis tubing.
2. Obtained the 5 unknown solutions from the instructor.
3. Once they were softened, for each dialysis tubing strip, tied a knot at the end of the dialysis tubing and would wet dialysis tubing when needed to keep them soft.
4. Syringe, or a pipette is used to fill a dialysis tubing with one of the unknown solutions until the dialysis tubing was about half filled. Tied off the tubing at the second end and set it on the table. 5. Repeated #4 for all the rest of the unknown solutions.
6. Recorded the initial mass of each dialysis tubing bag.
7. Placed the filled tubing into the correctly