Permeable membranes lab /iodine and vegetable oil

Introduction This experiment is based on the problem of whether the Ziploc bag will allow the iodine or starch to diffuse across the plastic "membrane". The hypothesis being tested is if the bag will allow the iodine to travel across the membrane and if it will react with the starch in the Ziploc bag. Procedure 1.<Tab/>Pour 25 mL of iodine into beaker 2.<Tab/>Fill about 1/3 of the …

…a deep purple in color and there is less iodine in the beaker than previously noted. The control starch in the test tube did not change at all. Conclusion The starch molecules in the bag were too large to diffuse through the plastic and therefore the iodine diffused into the bag and reacted with the starch changing it to the color purple. The control stayed unaltered because iodine and starch do not diffuse through glass.