Fick's Law of Diffusion (E1)

Question 1

Give the formula for Fick’s First Law of Diffusion.

Answer 1

J = -D * (ΔC)/( Δx)

Question 2

What does the variable J represent?

Answer 2

Flux

Question 3

What does the variable D represent, and why is it a negative value?

Answer 3

Variable D is the diffusion constant, and it is assigned a negative value because diffusion proceeds down the concentration gradient

Question 4

What is the absolute value of the diffusion constant D?

Answer 4

5e-6 cm^2 per second

Question 5

What does the variable ΔC represent?

Answer 5

The change in concentration (i.e., concentration gradient)

Question 6

What does the variable Δx represent?

Answer 6

The change in distance of the diffusion pathway

Question 7

What is the relationship between flux, concentration gradient, and change in distance when referring to Fick’s First Law of Diffusion?

Answer 7

Flux is directly proportional to the change in concentration (i.e., concentration gradient) and inversely proportional to the change in distance of the diffusion pathway

Question 8

Define flux.

NOTE: refer to the units of diffusion constant D

Answer 8

The amount of material passing through a cross-sectional area in a certain amount of time