Results:
Cube
Size
Total cube
volume
(cm3)
Total volume of the
decolorize cube
(cm3)
Percent
Decolorization
Surface area
of cube (cm2)
Surface area
to volume
ratio
1cm
1.586 cm3
0 cm3
100%
8.4 cm2
8.4 : 1.586
2cm
4.5 cm3
0.084 cm3
98.1333%
15 cm2
15 : 4.5
3cm
25.2 cm3
4.725 cm3
81.25%
53.4 cm2
53.4 : 25.2
Discussion:
A cell needs a large surface to carry out metabolic functions and as the cell grows it needs to carry
out more and more reactions. Diffusion is one of the most important processes of a cell in which it is used
to transport substances such as molecules, nutrients, water, oxygen, and cellular waste through the cell
membrane of a cell.
Diffusion occurs when molecules in an area of higher concentration move to an area of lower
concentration (Stouffer & Slisz, 2019). HCl is more concentrated outside the cubes than it is in the inside,
HCl is diffusing through the outer surface of each agar cube.
TOTAL CUBE VOLUME VS SURFACE AREA
72
3
25,2
18
2
4,5
1
1,586
11,76
0
20
SURFACE AREA
40
60
80
TOTAL CUBE VOLUME
When a cell grows, there is comparatively less membrane for the substances to diffuse through
resulting in the center of the cell not receiving the substances that it needs. Diffusion is less efficient, cell
processes slow and cells stop growing. The cell needs to divide into two smaller cells, which each have a
larger Surface Area:Volume ratio and can diffuse materials more efficiently.(edit mo to mamsh hahah)
That is why cells are small because they rely on diffusion for getting substances into and out of
their cells.
Appendices:
D. Diffusion and Surface Area
Volume of 0.1 M HCl: C1 V1 = C2 V2
1 M * V1 = 0.1 M * 1000 mL
V1 =
0.1 M∗1000 mL
1M
= 100 mL
% Decolorization
=
1.
volume of cube − volume of decolorized portion
volume of cube
(1.4 ∗ 1.4 ∗ 0.8) – (0)
(1.4 ∗ 1.4 ∗ 0.8)
x 100%
∗ 100%
= 100%
2.
(2 ∗ 1.5 ∗ 1.5) – (0.7 ∗ 0.4 ∗ 0.3)
(2 ∗ 1.5 ∗ 1.5)
4.5−0.084
∗ 100%
=
∗ 100%
4.5
= 98.1333%
3.
(4∗ 3 ∗ 2.1)– (2.1 ∗ 1.5 ∗ 1.5)
(4 ∗ 3 ∗ 2.1)
25.2−4.725
∗ 100%
=
∗ 100%
25.2
= 81.25%
Surface Area
= Length * Width * # of sides
1. 1.4 * 1.4 * 2 = 3.92 cm2
1.4 * 0.8 * 2 = 2.24 cm 2
1.4 * 0.8 * 2 = 2.24 cm 2
Total surface area: 8.4 cm2
2. 2 * 1.5 * 2 = 6 cm2
1.5 * 1.5 * 2 = 4.5 cm 2
1.5 * 1.5 * 2 = 4.5 cm 2
Total surface area: 15 cm2
3. 4 *3 * 2 = 24 cm2
4* 2.1 * 2 = 16.8 cm 2
3 * 2.1 *2 = 12.6 cm 2
Total surface area: 53.4 cm2
Bibliography
Stouffer, E., & Slisz, A. (2019, June 06). Retrieved from Rate of Diffusion through a Solution:
https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/S
upplemental_Modules_(Physical_and_Theoretical_Chemistry)/Kinetics/Rate_Laws/Reaction_Me
chanisms/Rate_of_Diffusion_through_a_Solution