help calculating a diffusion rate using Fick's equation.


by Wek
Tags: diffusion, equation, fick, rate
Wek
Wek is offline
#1
Feb19-12, 09:25 PM
P: 18
1. The problem statement, all variables and given/known data

Assuming:
Organism weight = 25 g
Organism lenght = 30 cm
[Na+ (ECF)] = 200 mM
[Na+ (water)] = 500 mM
ΔX(gill) = 6 μm
ΔX(skin) = 25 μm
A(gill) = 5.0 cm^2/gm
A(skin) = 10 cm^2/gm
Dk(gill) = 2 X 10^4 cm^2/s
Dk(skin) = 1 X 10^4 cm^2/s

Calculate the Na+ rate of diffusion through the skin using Fick's equation: (Dk)(A)((C1-C2)/dX)

2. Relevant equations

Fick's equation: (Dk)(A)((C1-C2)/dX)

3. The attempt at a solution

I'm not sure too sure if the answer that I'm getting is right. It seems to be too high and the units seem confusing.

Rate = (1 X 10^4)(10)((500-200)/25*10000) = 120 cm^3*mM/s*gm.

I am not sure if I should also use the weight and the length of the organism.

Thanks
Phys.Org News Partner Science news on Phys.org
Simplicity is key to co-operative robots
Chemical vapor deposition used to grow atomic layer materials on top of each other
Earliest ancestor of land herbivores discovered

Register to reply

Related Discussions
Fick's Law of Diffusion Introductory Physics Homework 1
Fick's law of diffusion General Physics 1
Application of Fick's First law (diffusion problem) Introductory Physics Homework 3
Molecular diffusion question; fick's first law Biology, Chemistry & Other Homework 2
Diffusion equation and fick law Differential Equations 2