| Before| After|
Color of liquid sack| clear| blue|
Color of liquid in beaker| dirty yellow| golden|
Glucose present Stick Test| no| yes|
Color of the test stick| No change in color| Green|
| Fresh| Salt|
Beginning mass of potato| 2.51| 2.16|
Texture of potato| Dry| Dry|
Overnight mass| 3.12| 1.84|
Overnight Texture| Hard, strong| Squishy, pliable|
Data and Analysis:
Iodine molecules entered the sack, while glucose molecules left the sack. When the iodine came in contact with the starch and changed color, the Iodine was entering the sack. You can tell the direction of the iodine by looking at the changing colors. The starch molecules remained in the sack because they were too large to pass through, so they couldn’t leave the sack. The glucose was able to get out of the sack, we know this because we tested the water with a test stick and it came back with a glucose positive result. Some molecules were able to move through the sack simply because they were smaller than others, but the starch molecules were unable because they were too large o pass. Finally, Diffusion is the net movement of particles from an area where there are many particles of the substance to an area where there are fewer.
The potato in the fresh water gained weight because the solute is moving toward the water. The potato in the salt water lost weight because the salt was at a high concentration level so it moved to an area of low concentration. Osmosis is the diffusion of water across a selectively permeable membrane.