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[Numbers without decimal points are considered infinitely precise. Show reasonable significant figures
and proper units.
Answers should be in reasonable units for the quantity.]
1. (5 points)
In the following table, insert the letter of the
best possible
definition from column b before
the word in column a.
(There is only one best answer for each.)
Column a
Column b
__a
1.
Fick’s second law
a.
Concentration change due to diffusion
__i___
2.
Flux
b.
Condition in which solvent molecules interact
weakly with a solute particle
__c__
3.
Perrin factor
c.
Determines the frictional properties of
nonspherical particles
__f__
4.
Prolate ellipsoid
d.
Diffusion of a spherical particle
__g__
5.
Random walk
e.
Means of carrying out faster sedimentation
than by gravitation
__j__
6.
Sedimentation coefficient
f.
Model obtaining by rotating an ellipse around
the major semiaxis
__b__
7.
Slip condition
g.
Model that uses a series of steps, with each
being uncorrelated with the previous one
__d__
8.
StokesEinstein equation
h.
Proportionality between flux and gradient
__h__
9.
Transport coefficient
i.
Quantity transferred through a given area per
unit time
__e__
10. Ultracentrifugation
j.
Usually reported in svedbergs
2. (5 points)
When two dice are thrown, what is the random probability that both of them land with the six
showing (i.e., what is the probability of throwing “boxcars”)?
The probability that one die will show a six is 1/6. The probability that the second die will show a
six is 1/6.
The probability that both will show a six is the product of these two:
P
= p
1
p
2
=
(1/6) (1/6)
=
1/36
CHEMISTRY 419
Spring, 2010 (2103)
QUIZ 1
February 18, 2010
NAME:
KEY ONE
Score ______/10
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View Full Document[Numbers without decimal points are considered infinitely precise. Show reasonable significant figures
and proper units.
Answers should be in reasonable units for the quantity.]
1. (5 points)
Calculate the pressure drop from one end of the aorta (
r
= 1 cm) to a point that is 1.00 cm
away, using the fact that blood flows at a rate
V
/
t
= 0.08 dm
3
s
1
and the viscosity of blood is 4.00
centipoise at a temperature of 310 K.
This is an application of Poiseuille’s law (and is example 24.16 in your book).
A rearrangement of
Poiseuille’s gives the equation:
t
V
r
L
P
4
8
Substitution of parameters from the problem into this equation, making sure they are all in SI units, gives
Torr
atm
Pa
s
m
m
m
s
m
kg
P
3
6
3
3
4
2
2
1
1
3
10
11
.
6
10
04
.
8
815
.
0
1
10
08
.
0
)
10
00
.
1
(
)
10
00
.
1
)(
10
00
.
4
(
8
2. (5 points)
The selfdiffusion coefficient of liquid water at 298.15 K is 2.25x10
9
m
2
s
1
.
Your Handbook
gives the viscosity of pure water.
Using these data, estimate the size of a water molecule, assuming it to
be a spherical particle of radius
r
.
(HINT: Assume that all equations work for all particles, regardless of
size.)
Use the StokesEinstein equation (slip conditions) to estimate the radius:
D
kT
r
4
. Putting in
data gives the following equation:
nm
m
s
m
s
m
kg
K
K
J
r
164
.
0
10
64
.
1
)
10
25
.
2
)(
10
937
.
8
(
4
)
15
.
298
)(
/
10
3806505
.
1
(
10
1
2
9
1
1
4
23
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 Fall '10
 Staff
 Chemistry, Physical chemistry, pH

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