PASCO ME-6940 Diffusion-Osmosis Apparatus - Manual (Page 5)

M o d e l N o . M E - 6 9 4 0 S a m p l e A c t i v i t y
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so that they both measure atmospheric pressure (102 kilopascals) at the start of the experiment. If you are using
other PASPORT sensors, calibrate them as instructed by the manual.
9. Experiment: Allow the processes of diffusion and osmosis to occur within the apparatus by leaving the experi-
ment setup in an "out-of-the-way" place where the ambient temperature will remain relatively constant and the
apparatus will be undisturbed for the duration of the experiment.
Sample Activity
Using 2.0 M Sucrose Solution and Distilled Water to Explore the Osmotic Move-
ment of Water across a Semipermeable Membrane
*To soak the membrane
Procedure
1. Soak one pre-cut dialysis membrane in distilled water for at least 30 minutes (at room temperature) to remove the
preservative on the membrane. When ready to use, rinse the membrane thoroughly with distilled water.
2. Obtain 40 mL of 2.0 M sucrose solution. To make 1 L of 2.0 M sucrose solution, place 684.6 g sucrose (table
sugar) in a large flask or beaker. Add distilled water until the solution's volume equals one liter. Place the solu-
tion on a hot plate/magnetic stirrer. Stir the solution while bringing it up to a boil. Continue until all of the solute
is dissolved in the water. Remove from heat and cool to room temperature before using. If you are not using the
solution immediately, cover and store in a sterile container in a refrigerator or cool place. Improper storage will
quickly result in mold growth.
3. Obtain 40 mL of distilled water.
4. Assemble the apparatus as described above.
5. Fill cylinder #1 with 40 mL of distilled water. Tilt the apparatus to get rid of any air bubbles around the mem-
brane.
6. Fill cylinder #2 was filled with 40 mL of 2.0 M sucrose solution. Tilt the apparatus to get rid of any air bubbles
around the membrane.
Materials and Equipment Materials and Equipment
PASPORT Interface Distilled water (40 mL)
Diffusion-Osmosis Apparatus 2.0 M Sucrose solution (40 mL)
Pre-cut Membrane Graduated cylinder (2)
PASPORT Dual Pressure Sensor Small beaker with distilled water*