Diffusion+Lab

=Diffusion Lab=

Introduction This lab demonstrated the process of diffusion through the use of agar blocks and HCl. After leaving the agar blocks in HCl for approximately ten minutes, the pinkish color faded closer to the middle, showing that the HCl has penetrated through the agar, changing its color. The HCl thus moved from an area with a higher concentration of HCl to the agar block, which has a lower concentration.

Lab In the lab, students used agar blocks and HCl to demonstrate diffusion. The agar blocks contained phenolphthalein, which made it pink. However, once the phenolphthalein touches an acid, or HCl, it turns into a clear color. We observed this process through the diffusion lab. 

Reflection Positive: During this lab, most of the steps went well because we did not face many problems. First, we efficiently measured the amount of HCl and quickly cut out the agar blocks. We also gained the desired results, which were similar to other lab groups. Negative: The worst part of this lab was when my group was not careful enough and splashed the HCl on the table. I felt that our group could have worked better together and been more productive. Also, two of the agar blocks my group cut out (2 and 3 cm cubes) turned out slightly lopsided (hopefully this did not have a huge effect). What was learned: This lab clearly exhibited diffusion for me. The phenolphthalein produces a pink color when mixed with a base, shown by the pink color of the agar block before it is placed in HCl. However, when phenolphthalein is in the presence of an acid, it turns into a clear color. This is revealed after the agar block is placed in HCl for ten minutes. The HCl, an acid, broke through the agar block as evidenced by the clear color on the edge of the cube. Difficulty: In this lab, the most difficult part was trying to cut the out the agar cubes. The knives did not cut a very straight side, making most of the cubes lopsided. This may have skewed our data, though not to a great extent. What could have gone better: In this lab, our group could have cut the sides of the cube smoother as well as be more careful with the HCl. If I could do this lab again, I would change these aspects of our conduct. If I could extend this lab, I would like to experiment with different materials and test the rate in which the HCl penetrates the surface.