The Effect of the Ratio of Surface area to Volume on the Rate of Diffusion in Agar Blocks
School Name
Heathwood Hall
Grade Level
11th Grade
Presentation Topic
Cell and Molecular Biology
Presentation Type
Non-Mentored
Abstract
The purpose of this experiment was to determine how increasing the Surface Area to Volume ratio (SA:V) affected the rate of diffusion in agar blocks. This relationship was tested to prove that a high SA:V ratio allows for the most efficient function of an object or organism. For example, a high SA:V ratio is used in the body to help cells faster perform reactions. When baking, often holes are put in the pastry so as to allow the pastry to cook faster because the heat will diffuse through the pastry faster since it has a greater surface area. The procedure consisted of three parts. Solutions of NaOH and HCl were made. Then agar was made and mixed with Phenolphthalein (PPT), a pH indicator that turns pink in basic solutions. NaOH, a basic solution, was added to the PPT soaked agar to make the agar a bright pink color. Different sizes of agar were cut out with different surface areas and volumes after they had turned a uniform pink color. Beakers were filled with HCl, and the agar blocks were dropped into the beakers. The time it took for the blocks to become clear was noted. The results of the experiment supported the hypothesis because the cubes with the largest SA:V ratio had the quickest rate of diffusion.
Recommended Citation
Dawkins, Lamar and King, Jaelen, "The Effect of the Ratio of Surface area to Volume on the Rate of Diffusion in Agar Blocks" (2017). South Carolina Junior Academy of Science. 38.
https://scholarexchange.furman.edu/scjas/2017/all/38
Start Date
3-25-2017 11:59 PM
Presentation Format
Written Only
Group Project
Yes
The Effect of the Ratio of Surface area to Volume on the Rate of Diffusion in Agar Blocks
The purpose of this experiment was to determine how increasing the Surface Area to Volume ratio (SA:V) affected the rate of diffusion in agar blocks. This relationship was tested to prove that a high SA:V ratio allows for the most efficient function of an object or organism. For example, a high SA:V ratio is used in the body to help cells faster perform reactions. When baking, often holes are put in the pastry so as to allow the pastry to cook faster because the heat will diffuse through the pastry faster since it has a greater surface area. The procedure consisted of three parts. Solutions of NaOH and HCl were made. Then agar was made and mixed with Phenolphthalein (PPT), a pH indicator that turns pink in basic solutions. NaOH, a basic solution, was added to the PPT soaked agar to make the agar a bright pink color. Different sizes of agar were cut out with different surface areas and volumes after they had turned a uniform pink color. Beakers were filled with HCl, and the agar blocks were dropped into the beakers. The time it took for the blocks to become clear was noted. The results of the experiment supported the hypothesis because the cubes with the largest SA:V ratio had the quickest rate of diffusion.
