Question

what is your prediction for this experiment?
a. iodine, glucose, and starch will be able to diffuse across the dialysis tubing membrane because they are the same molecular size
b. glucose and starch will be able to diffuse across the dialysis tubing membrane because they are the same molecular size
c. iodine alone will be able to diffuse across the dialysis tubing membrane due to its molecular size
d. iodine and glucose will be able to diffuse across the dialysis tubing membrane, but not starch due to its molecular size
what is your strategy?
a. i will place iodine, glucose, and starch into the same bag made of dialysis tubing and place the tubing into a beaker of water. i will then determine if they ar diffuse into the beaker.
b. i will place iodine on one side of the dialysis tubing and glucose and starch on the other. i will then test to determine if diffusion has occurred.

Explanation:

First Question (Prediction for the experiment)

To determine the correct prediction, we analyze the molecular sizes: Iodine (small molecule, like an ion or small covalent compound) and glucose (monosaccharide, small) can diffuse across a dialysis membrane, while starch (a polysaccharide, large molecular size) cannot.

• Option A: Starch is large, so it can't diffuse. Eliminate.
• Option B: Glucose (small) and starch (large) have different molecular sizes. Eliminate.
• Option C: Iodine can diffuse, but glucose (small) can too, and the option says "not iodine" which is wrong. Eliminate.
• Option D: Iodine (small) and glucose (small) can diffuse; starch (large) cannot. This matches the molecular size - based diffusion principle.

To test diffusion of iodine, glucose, and starch across dialysis tubing, we need to separate them on either side and test for their presence.

• Option A: Placing all in the bag and checking diffusion into water doesn't test the direction or separation properly.
• Option B: Placing iodine on one side and glucose/starch on the other allows us to test if iodine diffuses to the starch/glucose side (via color change for starch - iodine reaction) and if glucose diffuses (via glucose test), and if starch/iodine cross. This is a valid strategy to test diffusion.

Answer:

D. Iodine and glucose will be able to diffuse across the dialysis tubing membrane, but not starch due to its molecular size.

Second Question (Strategy)