.5!
ran/f
snow» all :
Problem 1 (2% points) Diffusion is occurring through a thin ﬁlm of liquid. Initially, the
concentration of the diffusing species in the ﬁlm is 0 throughout. At time = O, the-"coincﬁﬁﬁation
on the left side of the liquid is held to 10
Homework 2
Assigned January 13, due January 20
CHE 410 Spring 2017
Problem 1
a) Which of the following gases would you expect to diffuse fastest through argon and
why?
Ethane
2,3-dimethyl pentane
Propanol
b) The diffusion coefficients for three solutes in
Homework 1
Assigned January 9, Due January 13
CHE 410
NOTE ASSIGNMENT CONTINUES ON 2nd PAGE
Problem 1
A pool of contaminated water is lined with a 50 cm thick containment barrier. The
contaminant in the pit has a concentration of 2 mol/L, while the groun
Homework 4
CHE 410 Spring 2017
There are 4 problems in this assignment. Assigned January 27, due February 3
Problem 1 6.3-1 from the book
Problem 2 (a former exam problem)
Radon gas may enter a house by diffusion from the ground. Using the following simpl
Homework 2
Assigned January 13, due January 20
CHE 410 Spring 2017
Problem 1
a) Which of the following gases would you expect to diffuse fastest through argon and
why?
Ethane
2,3-dimethyl pentane
Propanol
b) The diffusion coefficients for three solutes in
Diffusion in Solids Units and Notes
Need an equilibrium relationship Cin solid = SCin liquid (or = SPin gas)
DAB units m2/s
m 3 (solute(STP)
concentration/pressure
m 3 (solid) atm
S (for gas)
How to convert the concentration to mol/m3?
divide by molar vol
1
Class Example 9 (based from book Example 13.42)
It is desired to determine the permeate composition and membrane
area needed to separate an air stream using a membrane 1 mil
(t=0.00254 mm) thick with an oxygen permeability of PA = 500 x 1010
cm3 (STP) c
1-27-17
Logistics
Homework 4 assigned
Check Canvas for homework solutions, lecture notes, etc.
Recap
Diffusion through a varying cross sectional area:
NA not constant, varies with r, z
NA* A constant (mol/s) = NA
write A(z) or A(r)
Today
Diffusion coeffic
Closed-book exam (no course materials allowed). Show all work and place a box around your answers. Describe solution procedure if
running out of time. Use additional paper for problem solutions (if required).
Acc = In - Out + Gen - Cons; dX/dt = mX for ba
Mae mwrg mode Lee81w \4
Wk 1 VP'VP ( mm were/m <A,B)
inN7 of A ngwef
VA yr WWW: PA]. P15)
/ WW -' Wham: t
QQA Pb . WkiC chYn .\ Ayn
LF' XF Lo,@
owlmInc oznr
flow was gnemoiA ?VQCSV\V
(u L? \L; P
(thaw Lo X o (2 as >
mm \/
W V 7 P PL
cfw_id 9A2 WORN "91>
LeeMe VGZ Mmmvxes ( MM 3 I
We m +0 SeagmAwns a cfw_'hjm M CME: \s
dena WV dquevew (/69 cfw_A . iswwfe'MS
A:OW : acgtmt b07\'~n5 fmr's 03 0x er+Nch\o5r Pregnge
ywvm me , 433mg son, games \0 Su\ve~n"$
cfw_3* ON sew/"Hcmbw WWW
Wmms Jzed- WMAbkeS "Awwgk m wu/
Homework 5 CHE 410 Spring 2017
Assigned February 3, due February 10.
There are 3 problems in this assignment.
Problem 1 (leftover from Homework 4)
A layer of salt of thickness 1 cm, of uniform concentration 10 kgmol/m3, is deposited in
the middle of a pol
Homework 5
CHE 410 Spring 2017
Assigned February 3, due February 10.
There are 3 problems in this assignment.
Problem 1 (leftover from Homework 4)
A layer of salt of thickness 1 cm, of uniform concentration 10 kg-mol/m3, is deposited in
the middle of a po
_ hog-c a
M3 055 — _ - Mlil! . '
6% l -. i a- my
_ _ 1 :2 A: I-
A A ‘: ,1 ,
Iv lYl-EAWVEAW
‘m-‘-A‘-‘g.‘v
1174-917 -' a Problem 2 (20 points):
Pyrex glass is almost impermeable to all gases except He. Suppose a natural gas —
He mixture is contained in a
Homework 4 CHE 410 — Spring 2015
Assigned January 30, due February 6
Problem 1 — Problem 7.6-1 from your textbook (Knudsen diffusion)
Problem 2 _ Problem 7.6-3 from your textbook (Knudsenftransition region diffusion)
Problem 3 — Problem 7.1-4 from your te
CHAPTER 3
Diffusion in Concentrated Solutions
Diffusion causes convection. To be sure, convective ow can have many
causes. For example, it can occur because of pressure gradients or temperature differences. However, even in isothermal and isobaric systems
CHE 410, Fall 08. In class examples
Class Example 1 Mass Balance Review
Time to fill a balloon
A balloon, initially at a volume of 0.01 m3 and filled with a gas at a pressure of 1 atm, is to be
filled by flowing in helium at a rate of 0.1 m3/s and a press
3 / Diffusion in Concentrated Solutions
78
Table 3.4-1 Mass balance for species 1 in various coordinate systems
Rectangular coordinates
qc1
qn1x qn1y qn1z
r1
qt
qx
qz
qy
Cylindrical coordinates
qc1
1q
1 qn1h qn1z
r1
rn1r
qt
qz
r qr
r qh
Spherical coord
You take a new job in a chemical plant and your first
assignment is to figure out what to do about a bucket of a
toxic chemical left behind. Your predecessor had left the
bucket out back of the plant, but your company is in
trouble with the EPA because th
Approximate Schedule and Reading Material
Note: Weekly reading assignments given in class are considered the definitive list of textbook material subject to
examination not this list. All material covered in class, which will draw from sources beyond the
HOMEWORK 7, CHE 410, Spring 2017
Posted 2/20/17, Due Wednesday, 3/1/17
There are 5 problems in this assignment.
Problem 1 (you can start this week)
You are to separate an CH4/CO2 stream using a membrane process. The membrane to be used is
silicone rubber
NaCl in kg/m^3
0.00
NaCl in mol/kg H2O
0
Table of data from book
NaCl in mol/kg H2O NaCl in kg/m^3
0
0
0.01
0.47
0.1
4.56
0.5
22.55
1
45.8
2
96.2
c2
c1
copy pi 1 from interpolate
pi 1
pi 2
d(pi)
dP
Aw
As
Cw2
B
R
C2 from R
Nw
Ns
INTERPOLATE
0
0.015556
0.10
Materials balance review:
Volumetric flow rate (m3/s)
Cross-sectional area (m2)
velocity (m/s)
Molar average velocity: vm
Molar fraction of A
Velocity of A
Convection: all molecules move (together) along one direction
(Example: fluid flow)
Diffusion: rand
Homework 6
CHE 410 Spring 2017
Assigned 2/10/2017, not collected or graded due to exam.
Problem 1
You are to separate an O2/CO2 stream using a membrane process. The membrane to be
used is silicone rubber with a thickness of 2.00x10-3 cm. Permeabilities ar