Mt. Pleasant Classical Academy

Our science lab on Monday dealt with Osmosis — the movement of molecules from areas of high concentration to an area of low concentration. Inside this permeable membrane was a solution of starch and sugar while the beaker contained an iodine solution. Soon the iodine diffused across the membrane and into the bag turning the solution from white to purple. COOL!! Starch molecules are unable to diffuse across the membrane so the beaker containing the iodine solution remained yellowish-tan.

I love when science labs work.

We could see a distortion at the base of the bag from a material diffusing out of the bag. We’re pretty sure it was the glucose diffusing out across the membrane however we weren’t able to detect it with our Benedict indicator later on in the lab.