The presence of glucose in the starch solution was confirmed by the positive result obtained in the dialysis experiment. Starch molecules are too large to pass through the dialysis membrane, while smaller molecules like glucose can diffuse through. This demonstrates the selective permeability of the dialysis membrane.
In the dialysis tubing bag experiment, if glucose and I2KI are present inside the bag, the color of the I2KI solution will turn blue-black due to the reaction of iodine with starch present in the glucose solution. This color change indicates the presence of glucose inside the bag.
The iodine solution in the baggie would diffuse into the beaker containing the starch. The iodine molecules would interact with the starch molecules, resulting in the formation of a dark blue or black color, indicating the presence of a starch-iodine complex.
In this scenario, the concentration of solutes (the glucose and starch) is higher inside of the dialysis tubing than it is outside. As such, water will diffuse (via osmosis) into the dialysis tubing causing it to swell.
I'm assuming this is in reference to an experiment where you put a starch in dialysis tubing, and then put iodine in surrounding solution. Dialysis tubing has a limit of roughly mwco (molecular weight cut off of 10,000). Iodine has a molecular weight of roughly 126, so it can pass through. On the other hand, starch is a polymer of 1000's of glucose molecules. Glucose (C6H12O6) has a molecular weight of roughly 180. 1000 * 180 = 180,000, so glucose cannot pass through the dialysis tubing. In this experiment you should see the sealed tubing turn purple-pinkish after the iodine diffuses through. The outside solution should remain the same color.
the color of the leaf become brown-black after the iodine solution was added.
Cells that contain starch will turn blue-black when tested with iodine solution, indicating the presence of starch. Cells without starch will not change color in the presence of iodine solution. This test is commonly used to identify the presence of starch in cells.
Sugar was likely found in the experiment because the starch was broken down into simple sugars through the process of digestion in the saliva. This breakdown of starch into sugars can be catalyzed by enzymes present in saliva, leading to the presence of sugar in the solution.
You can determine if iodine entered the dialysis bag containing starch by performing a simple iodine test. Add a few drops of iodine solution to the bag. If the iodine turns blue or purple, it means that iodine has entered the bag and reacted with the starch inside.
Starch is not a solution.
Well what i think is that The water outside of the "cell" will change colors and not the "cell" :D
The starch indicator solution will diffuse out of the bag (cell) into the beaker, changing the color of the starch solution to a blue, purple, or black color (assuming that it's iodine). The color of the indicator solution inside the bag will not change, because only the glucose can diffuse into the bag, but the starch cannot diffuse into the bag.