1. Point Pleasant Bridge
Delatte, Norbert J. Beyond failure forensic case studies for civil engineers. Reston, Va.: ASCE
Press, 2009. Print.
Point Pleasant Bridge (Silver Bridge) was a suspension bridge completed in 1928
connecting Columbus, Ohio, to Char
CBEMS 45B Homework #5 (Due 2/21/2017)
1. Please describe the application conditions for following energy balance equations:
a. dU Q PdV
b. dU H dM Q PdV
c. M U 2 U 1 Q W
d. M H 2 H 1 Q W s
2. What is the physical meaning of entropy?
3. An isolated chamber
CBEMS 45B Homework #1 (Due 1/19/2017)
1. Describe the contributions to the establishment of the first law in
thermodynamics by J.R. Mayer, L.F. von Helmholtz and J.P. Joule,
respectively.
2. How do you understand the analogy discussed in the lecture, betw
Homework #2 (Due 1/26/2017)
1. Derive the general balance equation for a chemical reacting system in differential
form and difference form on mass and molar basis, respectively.
2. What is the key contributions by J.W Gibbs to the modern thermodynamics
3.
Homework #4 (Due 2/14/2017)
1. What is the lever rule for two-phase mixtures?
2. What is a reference state? Explain with expressions of the internal energy and the
enthalpy for an ideal gas.
3. What is Dulong and Petit law?
4. What is the relation between
CBEMS 169
Spring 2016
Homework #1
Due April 6, 2016 in class
1. Consider an electron accelerated in a vacuum between two parallel plates 1 m
apart. If you apply 50,000 V across the plates, and the electron starts at rest on
the surface of one plate, what
CBEMS 169
Spring 2016
Homework #3
Due April 20, 2016 in class
1.
(i)
(ii)
Write the ground state electronic configurations for the valence shell electrons
of N, F, Al, and Cu, showing schematically the spins of electrons in each
orbital.
Write out the fou
CBEMS 169
Spring 2016
Homework #8
Due May 25, 2016 in class
1. Draw the electronic energy band diagrams for p-n junctions in the following
configurations. Label the p-type side, n-type side, conduction band, valence band,
and Fermi level in each case:
(i)
CBEMS 169
Spring 2016
Homework #9
Due June 3, 2016 in class
Note: Sze uses work function, barrier heights in volts, not energy. However the energy
of an electron with a given voltage is just the magnitude of the voltage. (e.g. barrier
height of 1 V means
CBEMS 169
Spring 2016
Homework #7
Due May 18, 2016 in class
1. A one-sided p+-n Si (which means NA > ND) junction at 300 K is doped with NA =
1.5 1020 m-3, consider Vbi = 0.4 V.
(i)
You measure a junction capacitance of Cj = 8.0 pFcm-2 at VR = 5.0 V. What
CBEMS 169
Spring 2016
Homework #5
Due May 6, 2016 in class
1. Sketch the electronic band structure of (i) a metal, (ii) a semiconductor and (iii) an
insulator, like in Fig. 7.17 from the book.
Label the Fermi level on (i) - (iii) and shade in occupied sta
CBEMS 169
Spring 2016
Homework #4
Due April 27, 2016 in class
1. On a single plot sketch the Fermi-Dirac distribution vs Energy for each of:
(i)
T=0K
(ii)
T = 300 K
(iii)
T is very large (approximately infinite).
Label the position of the Fermi level on t
CBEMS 169
Spring 2016
Homework #6
Due May 11, 2016 in class
1. Considering that N e N h = N i2 in a given semiconductor, find the ratio
Nh
which
Ne
yields minimum conductivity. Assume that collision times for electrons and holes
are equal and that
me*
= 0
CBEMS 169
Spring 2016
Homework #2
Due April 13, 2016 in class
1.
(i)
(ii)
(iii)
Perform the following calculations for objects at room temperature (T = 300 K)
What is the effective mass of an electron with a de Broglie wavelength of 8 nm?
What is the de B
Discussion Sec+on
CBEMS 45A Fall 2016
October 18th 2016
TA Pamela B. Besada-Lombana
Prof. Nancy A. Da Silva
From Statement to Flowchart
Problem 4.17
(Pg. 178)
From Statement to Flowchart
Problem 4.17
Required deniNons:
Lower ammabilit
A gas mixture containing C6H6 (benzene), CO2, O2, and N2 leaves a solvent recovery unit. The stream
contains 13.0% CO2 and 4.0% O2. The partial pressure of benzene in this stream is 85 mm Hg and the total
pressure is 760 mm Hg. This gas is then compressed
CBEMS 45A Final - p. 4
3. [35 pts.]
A biofuel plant produces ethanol by yeast fermentation, and the ethanol is recovered using a distillation
column. The gas stream exiting the distillation column contains ethanol and water. This stream is then is
fully c
CBEMS 45A Final - p. 5
Ar 3
5. 20 ts.
_ l p l
A gas mixture containing CGH6 (benzene), C02, 02, and N2 leaves a solvent recovery unit. The stream
contains 13.0% C02 and 4.0% 02. The partial pressure of benzene in this stream is 85 mm Hg and the total
pres
A biofuel plant produces ethanol by yeast fermentation, and the ethanol is recovered using a distillation
column. The gas stream exiting the distillation column contains ethanol and water. This stream flows into a
cooler as is fully condensed to a sub-coo
HW #3 Solution
1-3. Please find answers from your lecture notes.
4. Since for the ideal gas, enthalpy is a function of temperature only,
thus, H1(P1,T1) = H2(P2,T2) becomes H1(T1) = H2(T2),
which implies that T2=400C.
5. system: contents of the turbine (o
Sample Midterm Exam
CBEMS 45A Midterm - p. 1
1. [5 pts.] Short Answers
Composition of a mixture in wt % is approximately the same as the composition in mol %. _ (T/F)
The equation y=axb will be a straight line on semi-log paper. _ (T/F)
A gauge pressure o
HW 7 Solution
1.
2.
3.
4.
Initially, Ti =298K, Pi=400bar, Vt=0.045m3
=
=
6.19410-5m3 , = =726.5 mol
Final P is 1.013bar and final T is unknown, will be found by equating the initial and final entropies. Guess final T is 200K
Pf=1.013bar, T=50K, =
S final
CBEMS 45A Homework 1 Solutions
Fall 2016
1. a) A mixture contains sugar (MW=180.) and salt (MW=58.4). There is three times as much sugar
as salt (by mass). If total mass of the mixture is 495 g, how many moles of sugar are there?
+ = 495
3 =
495 = + (3
CBEMS 45A: Chemical Processing and Material Balances
QUIZ #5
. n C 3 H1
11] C3H8 n O;
O
1. Your camping lantern burns propane gas (C3H8). ON a
(a) Write and balance all chemical reactions that could occur. 7 O. n co 9
. n- Ni C o
C3\-\x+ 30; 3; 4 Rug 3
CBEMS 45A: Chemical Processing and Material Balances
QUIZ #4
1. Flowchart: Tamoxifen is a drug than binds to estrogen receptors and inhibits the growth of breast
cancer cells. To manufacture tamoxifen tablets, a stream of finely ground powder containing
t
HW #4 Solution
1 ~ 8. Please find answers from your lecture notes.
9. An isolated chamber with rigid walls is divided into two equal compartments, one
containing ideal gas at 2 MPa and 600 K and the other evacuated. The partition
between the compartments