Four bags are filled with a 10% starch solution. The membrane of each bag contains microscopic pores that are large enough to let small water molecules across but too small to let the larger starch molecules across.
Each bag is placed in a separate beaker as follows:
Bag I is placed in distilled water containing no starch (0% starch).
Bag 2 is placed in a 5% starch solution.
Bag 3 is placed in a 10% starch solution.

Bag 4 is placed in a 50% starch solution.

 

The filled bags are weighed prior to placement in the beakers and then at regular intervals over the next hour. The weight of some of the bags changed, and some did not. Answer the following questions based on the expected outcomes of this experiment.

1. Which bag should weigh approximately the same at the end of the experiment as it did at the beginning of the experiment? Why?
2. Which bag is expected to be the heaviest at the end of the experiment? Why?
3. Which bag is expected to be the lightest at the end of the experiment? Why?
4. If the bags had pores that also allowed the starch molecules across, would the outcomes be different? (Yes or No)

When orange iodine is exposed to starch it turns blue-black. In an experiment, you placed a cornstarch solution in a small plastic bag. Next, you placed the the bag in a beaker of water containing 10 drops of iodine. If the solution in the plastic bag turned blue-black (Check all that apply)

the plastic bag was permeable to cornstarch.

the plastic bag was permeable to iodine.

the iodine moved into the plastic bag.

the cornstarch moved into the beaker.

the plastic bag was selectively permeable.

2nd part of my biology lab experiment I mixed water with iodine in a bag then placed the bag ( amber color) in a glucose and starch solution (clear) in a beaker for 60 mins, After 60 mins the solution in the bag was appeared dark blue on top and clear on bottom. Once I took the bag out of the beaker, the solution appeared light blue, almost clear. The solution in the beaker was light blue with dark blue along the top and dark blue dots throughout the solution. I did a glucose test strip for the solution in the bag and the color was dark green. I did an IKI indicator for the solution in the bag and it came back amber. I then tested the solution in the beaker, glucose strip came back dark green and the IKI indicator color came back dark blue. So on my lab question it is asking me to explain why the materials moved the way that they did in beaker / bag 1 in my dialysis bag experiment. ( Give info on water, glucose and starch.)

A bag constructed of a selectively permeable material (soluble to water and insoluble to all solutes) is filled with a 10% glucose solution and sealed tightly. Describe the osmotic relationship when this bag is placed in a beaker containing:

a. 20% glucose solution:

b. 10% sucrose solution:

c. 20% starch solution: