Osmosis and Diffusion lab part 2

Today in class we continued to explore the concepts of diffusion and osmosis. We conducted two different types of experiments: one was to test the rate of diffusion  of KI through different size blocks of a substance and the other was to test the diffusion of a starch and glucose mixture.  Before we conducted the experiments, we graphed part three and part four of the experiment. 

1st experiment: 

1. Cut three different size blocks of the substance 

2. Then put them in three different size beakers 

3. Then pour KI over each one an make sure they are completely covered 

4. After about 15 minutes, take them out

5. Cut them in half and find the area of the block that didn't have KI in it 

6. Then find the percent of that area out of the total area 

Significance: 

We did this experiment to compare the diffusion rate and how size affects the diffusion rate.

2nd Experiment: 

1. Fill the cell with a starch and glucose mixture 

2. Test tap water for glucose and test mixture for glucose 

3.Then place the cell in a beaker and put in enough water to cover it

4. Then after about 15 minutes take 1ml of the water and put it into a vile 

5. Then add a drop of Benedict's substance to the vile to test for glucose

6. Then put the vile in boiling water and observe 

7. Then add iodine to the remaining water and cell 

8. The starch should react with the iodine and turn a dark blue color 

Significance:

We did this experiment to show that the glucose molecules can move thought the semi permeable membrane, while the starch molecules cannot because of their larger size.