Iodine is permeable to a plastic bag because the starch's molecules are too large to pass through the bag (starch is a complex sugar made of a large chain of monosaccharides), while the Iodine can pass through since iodine is usually only two Iodine atoms (I2).
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.
I am not quite sure what happens when corn starch and iodine are mixed but when corn starch, iodine and water are mixed, it creates a purple solution. The darkness of the colour mostly depends on the iodine. Without the starch with iodine and water, it is deep yellow or brown.
Solutions tend to move from areas of high concentration to areas of low concentration. So if a bag is permeable to starch, the starch will rush into the bag.
Iodine is reactive with plastics and can cause them to degrade, leading to contamination of the iodine and possibly releasing toxic fumes. It is better to store iodine in a glass container to maintain its integrity and prevent any unwanted chemical reactions.
Because iodine is an atom and it can permeate the pores of the plastic bag. Iodine can also be very reactive, so storing it in a plastic bag might cause reactions with other substances... depending on what you put near it.
After 20 minutes, the glucose molecules will diffuse out of the bag through the partially permeable membrane because they are smaller in size than the starch molecules. The starch molecules, being too large to pass through the membrane, will remain inside the bag.
If the phenolphthalein solution turns pink, that means that the plastic bag is permeable to ammonium hydroxide. If it remains colorless, then the plastic bag is not permeable to ammonium hydroxide. If the contents of the plastic bag turn pink, then the plastic bag is permeable to phenolphthalein. If everything remains colorless, then the bag is impermeable to both ammonium hydroxide and phenolphthalein.
Iodine molecules are much smaller than oxygen molecules, so they can pass through small openings in the plastic bag. However, the plastic bag is impermeable to air, so you cannot get enough oxygen by breathing through it. This can lead to a lack of oxygen and potentially suffocation.
Starch presence in a leaf suggests an excess of glucose produced during photosynthesis. This excess is converted and stored as starch, serving as an energy reserve for the plant. Starch accumulation also indicates that the plant is undergoing optimal photosynthesis.
The starch remains in the dialysis bag because the molecules are bigger than the pores. The potassium-iodide enters the bag (this can be determined because the liquid inside the bag turns black or blue as the iodine reacts with the starch). And the glucose leaves the bag, you probably tested the water in the beaker with a small strip of paper that would have changed color indicating the presence of glucose.
Yes, the cell membrane is selectively permeable, meaning it allows certain molecules to pass through while blocking others. This property helps regulate the movement of ions and molecules in and out of the cell, maintaining cellular homeostasis.
Does not allow matter to pass, but energy (light, heat, etc) is allowed to enter.