Diffusion Lab : 9/4/13

      In class 9/4/13, we did two labs. In part 1, we made a cell and filled it with a solution that had 15% glucose and 5% starch. We placed this cell in a cup and added water. Then we added iodine to the water and saw that inside of the cell that had the clear solution changed to a bluish black solution. This reaction occurred because of diffusion, the higher concentration iodine moved into the lower concentration solution inside the cell. Then there was a reaction between the iodine and the starch that occurred which resulted in the solution inside the cell to turn into a bluish black color.

 

 

      The second lab we did also tested diffusion. We had three pieces of agar cut into different shape that were sitting in potassium iodide. We measured the surface areas of each piece and place them into a beaker filled with water. Then we added iodine and waited three minutes. We found that the pieces had changed to a bluish color. We took the pieces out and cut them to see the insides. The insides were still white because we did not wait long enough for the diffusion process to complete.