Fick's law

  • Thread starter ibysaiyan
  • Start date
  • #1
ibysaiyan
442
0
1.
Homework Statement

Question
This is an experiment on a dilute isotopic mixture of helium gas. A spherical vessel of
diameter 1 m is first filled with 4He gas to one atmosphere pressure. Then a small
amount of 3He gas is introduced through a valve on one side of the vessel. Make a
rough estimate of how long one must wait before a uniform mixture has formed (use
the result for the time dependence of the root mean square travel distance in a
random walk in 1D.) Suggest a better way to make a uniform mixture.


Homework Equations



Area = pi (diameter/2)^2 , pv =nrt , ficks law of diffusion , Mass flux = 1/3lv

The Attempt at a Solution


I am not sure where to start from. I am reading about fick's law of diffusion right now however I'd love tobe pointed out in the right direction.

Since the question asks for time dependence then isn't second law the most obvious equation to use ?
edit: hm.. as i was reading i came across this idea.. how about i get the area first, then divide volume by area to give me the 'length' which i can plug into ficks equation if I am not mistaken.
Appreciate your help.
 
Last edited:

Answers and Replies

  • #2
ibysaiyan
442
0
Anyone?
 
  • #3
ibysaiyan
442
0
Never mind.. can one of the moderators please close this thread. I have figured out the final answer,etc.. took me countless sheets but it was worth it.
 

Suggested for: Fick's law

  • Last Post
Replies
5
Views
7K
  • Last Post
Replies
1
Views
419
Replies
0
Views
2K
  • Last Post
Replies
13
Views
3K
  • Last Post
Replies
5
Views
1K
Replies
2
Views
6K
Replies
0
Views
6K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
1
Views
2K
Top