(adsbygoogle = window.adsbygoogle || []).push({}); 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

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# Homework Help: Help calculating a diffusion rate using Fick's equation.

Can you offer guidance or do you also need help?

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