The aim of this experiment was to examine the effects of the surface area to volume ratio of theoretical cells on the rate of diffusion, with the results of this experiment proving to support the proposed hypothesis. This hypothesis proposed that a decrease in the rate of diffusion would be the result in a decrease to the surface area to volume ratio based on the disproportional rate at which the ratio expands. Using agar jelly containing phenolphthalein (universal indicator for pH) and sodium hydroxide, cubes that were made with varying dimensions therefore obtained varying surface area to volume (SA:V) ratios . These were submerged in a solution of hydrochloric acid as the change in colour was measured which indicated the percent volume diffused…show more content… These alterations consequently decreased the surface area to volume ratio from 6 to 3 to 2 respectively. As the dependent variable of the experiment, the rate at which diffusion occurs was measured by calculating the perimeter of colourless agar surrounding the cube itself after a period of 5 minutes – representing the distance diffused into the cell. Consistent observations and photographs were additionally noted. These variables were incorporated into the experiment by firstly forming the agar jelly solution by adding 4.6g of agar powder to a mixture of 180ml distilled water and 20ml sodium hydroxide. After adding 5 drops of the phenolphthalein indicator to the boiling solution, the jelly was set aside to cool. The agar jelly was then measured and cut into cubes of their respective dimensions being sizes of 1x1x1cm, 2x2x2cm and 3x3x3cm. These cubes were then added to each of the 40ml hydrochloric acid filled beakers before being removed and observed after 5 minutes. These steps were each repeated a further 3 times in order to calculate the percentage volume of diffusion (indicating the diffusion rate), ensuring accurate data and correspondingly representing the effects of surface area to volume
