exam1fall07sol - CEE 3104(Marr Exam 1 2007.09.27 Name last...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: CEE 3104 (Marr) Exam 1 2007.09.27 Name last, first HONOR CODE I have neither given nor received unauthorized assistance on this exam. Signature Potentially useful equations Qmax = 034114 hv c = 70v 2898 Q E _ q = V5.1...re = (413) nR3 Asp...re = 47:18 Physical constants Avogadro’s number NA = 6.02 x 1023 mol'1 Ideal gas constant R = 82.05 x 10"5 m3 atrn mol" K" = 8.314 J mol" K" Speed of light c = 3 x 108 m s'1 Stefan-Boltzmann o = 5.67 x 10'8 w m'ZK" Molecular masses H = 1.01 g mol" c = 12.0 g mol" N = 14.0 g mol" 0 = 16.0 g mol" F = 19.0 g mol" C1= 35.5 g mol" Ca = 40.1 g mol'1 Water density p520 = 1000 kg m'3 = 1 kg L'1 = 1000 g L'1 = 1 g ml'l = 1 g cm'3 Conversion factors Length 1m=3.281ft 1km=0.6214 mi Volume 1 m3 = 1000 L 1 ft3 = 0.02832 m3 1 gal (US) = 3.785 L Mass 1 lbrn = 0.4536 kg Energy 1kcal=4.185kJ 1Btu=1055J lJ=le" Temperature K = °C + 273.15 °C = 5/9 * (°F — 32) Normality 1 meq L" = 50 mg L" as CaC03 Pressure 1 atm = 101,325 Pa _--'- IOSSible earned - oss1ble earned —___-.3- “mi- = in EU]: ('0 (D !% ! 10for SHOW YOUR WORK! You do n_ot have to answer in complete sentences. 1) In a Rolling Stone article entitled, “Can Dr. Evil Save the World?” proposes to combat global warming by burning sulfiJr to create particles and then clumping them out of high-flying airplanes. a) 4 oints For this to work best, should the particles absorb, reflect, or transmit shortwave/visible adiatio ? pg [30 ' KW b) (4 points) Should the particles absorb, reflect, or transmitilongwave/infiared Fadiation? 75mg We? eat/p77: :r KW CW7” 2‘? #425; WWW c) (4 points) Would you expect the presence of the particles to make the ozone hole better, worse, or to have no effect? Why? uM/ée .— mpw: facade. area. 36F VINO/0 W5 mammj firm/t“ Cleave/7‘ CMWIM {Era/Varrs % czar/ye Cifmrme. 2) Ozone hole chemistry a) (4 points) Using the terms “stratosphere” and “troposphere,” explain the meaning of the phrase for ozone: “Good up high, bad nearby.” mm m W. fVm‘osp/Lm Ls gym! bem' . ML prettier; M5 19W 06V {WW4}, win/(ch Cour/Lees than. cat/mac»? 02m M Ma Hflmfiflhflflf {5 bad because we: have: 7L6 b/EWLZ if, M If Cid/£29: WS/Irajmgz iffrfflfim_ b) (4 points) Methyl bromide (CH3BI‘) is used to sterilize soil, especially in the production of strawberries. It is also an ozone-depleting gas that is 0.4 times as strong as CFC-l 1. Why are HCFCs a good replacement for CFCs with respect to ozone destruction? The OH head ts eaSIer 7‘9 éreqk Hart Hue HCFC 6m 20f7 c) (4 points) Write two reactions that describe the catalytic destruction of ozone by the bromine (Br) radical. The chemistry is analogous to that for chlorine. 05 l’flf ,9 5r? +02, fir0¢0 “'9 Br +0?— 3) Environmental engineering applications (based on O’Bn'en and Gere presentation) a) (2 points) What is the purpose of pumping lactate underground to try to-treat a groundwater plume containing the contaminant perchlorethylene? Hint: the technology is known as “enhanced bioremediation.” Leda/fl: W5 pm? Mamba? [W‘Ea/c dawn m5 flare/Jam 57%7 @142 b) (2 points) Give one reason why the Patuxent water treatment plant was upgraded. 9 MW “face/23;: 0f @ Repair W Car/052m c) (2 points) What are environmental engineers looking for when they look into manholes or run smoke or dye tests in sewer pipes? Leaks Info WJVSTWL 150444 mic/aw (rMu/W) of mfi/v‘rawyt (av/WW 30f7 4) Suppose a greenhouse effect enhancement raises the surface temperature of the earth to 291 K, melting enough snow and ice to reduce the albedo to the point where only 100 W m'2 are reflected. The atmospheric window is closed somewhat so that only 30 W m'2 now pass directly from earth’s surface to space. The latent and sensible heat transfer (convection and evaporation) to the atmosphere do not change. Incoming 342 W m"2 Through Radiated Reflected window to space 100 Z Convection, lAbsg;bed evaporation Atmosphere 102 // ' /////, ////l1E$:/lll’/$I’Il’llllllg %fi7lf/lf/Iflff/I/3/El/I/Ifig/ifllg /A//b sorbed Radiated at Back radiation W ////II: 91 K I Y a) (GI points) Find the solar radiation a sor ed at the surface, W. b) (‘8 points) Find the surface radiation, X, absorbed by the atmosphere. ”W ",7: 0le : (aw/0's film) (2‘?! l4)": 407 a: surfiW—l rad/Liam 40’? = 30+X =>I><== $77 “flag c) (4 points) Find the back radiation fiom the atmosphere to the surface, Y. Eda/ML ajf' Suffitcasz \i: 30+377+I02, [75- : 0 I I UJ+Lf 30+X+I Z Y: 33% Uymz' d) (4 points) Find the outgoing radiation from the atmosphere, Z. This may be different from Y because the top and bottom of the atmosphere can be at different temperatures. 4) Suppose a greenhouse effect enhancement raises the surface temperature of the earth to 2297 K, melting enough snow and ice to reduce the albedo to the point where only/2100 W m'2 are reflected. The atmospheric window 15 closed somewhat so that only 30 W m'2 now pass directly from earth’s surface to space. The latent and sensible heat transfer (convection and \Ql? evaporation) to the atmosphere do not change. Incoming 342 W m'2 Through Radiated Reflected window to space 100 Z Convection, 1Ab5g7fl36d evaporation Atmosphere 102 ‘1 l/I/I/I/l/I/I/ll//////////ll/I/I/I/If/f / ///// //// Earth” 3 surface é Absorbed Radiated at Back radiation W T = 297 K Y a) (5 points) Find the solar radiation absorbed at the surface, W. Provide units. Edna/teem HAW/V5 fad/(W Sal=100+é7+ u) =>l176 ”/le b) (8 points) Find the surface radiation, X, absorbed by the atmosphere. 3 W 3 q! I“ p (07240 3 mmmsm L4)“: L14} Ill/ma 13%: 201 {93 SUFQCQ 30+X: HLH Q im e) (5 points) Find the back radiation from the atmosphere to the surface, Y. Jada/ML U Surface, URI+V=L1LLH+IOZ g W308 Low} 17': d) (4 points) Find the outgoing radiation from the atmosphere, Z. This may be different from Y because the top and bottom of the atmosphere can be at different temperatures. bah/mu?— cm S Page. ng/Z: i004“ 30+? ‘%\w 40f? 5) The compound diacetyl (C4H502) 15 used to flavor popcorn and has also been shown to severely damage the respiratory system of rats at a gas-phase concentration (partial pressure) of3 52 x 10“ atm (Hubbs et a1. ,.2002) \30 a) (12 s) If the liquid used to flavor popcorn contains a diacetyl concentration of 5 g L how does the equilibrium gas-phase concentration compare to 1the level found to be angerous in rats? The Henry s constant for diacetyl IS 190 M aim"1 at room temperature (Gaffney et a1, 1987). 5:591 ”4 HO W 04 4 a 52} 04W "Paws!" Ho m- 3"“) W ' W flfiwflbfium PMUZTQ (5 MSWW {W Wm M law! QCJU/M 7’?) be Was 1 WW be, Cancarmol, b) (4 points) The molecular structure of diacetyl is shown below. Is it an alkane, alkene, alkyne, or aromatic? What functional group(s) does it have? CH3 0\\ / CHC “ac Cafbo-mgfl ( We) 50f7 6) According to the Center for Disease Control, the optimal fluoride (F ‘) concentration in drinking water to reduce the risk of tooth decay is 0.7-1.2 ppm. a) (6 points) If you add calcium fluoride, CaF2(s), to water and create a saturated solution, what is the resulting fluorine concentration [F'] in units of M? The reaction is j a , Can <—> Ca2+ + 2 F with a solubility product of3.0 x 10'“. f) y [Caz’fJEFJ-L— g): H04! Calcs.) —9 l CW and 2 F” 5> [WU—”HF? .3 (aw) mix?" 42:10“ ’" in]: (mama-"é : swam w b) (4 points) Is your result greater than or less th 1.0 ppm" My}; H’fl fi/flgfl 0-14 mg? l [000 #mfij 3‘1*W(L)(3H~m) 7"?er {\(LSULU' isi> (.0me r .50 We, WWI—D be UflsxyhamIEA c) (4 points) How much Can do you need to add, in units of mg, to l L of water to achieve a fluoride concentration, Xp_, 0 ppm. Comm l ppm -»> ”9/1,. chszsl—MJ +205'):78.l 9M {PPM (1.91“): I ’V‘Q/L 03( F: but me, ms! +0 add Wm M (W4 ”F C46— 41) W lath H: F' ~192qu (2%,. [mg FOWFFXRMFW) (785562951 - IT 5mm Call-p2 ”Built— 60f? d) (4 points) Write the electroneutrality equation for all ions present in the solution. 2mm + me = [F'lrfoufl e) (8 points) In theory, you could also use hydrofluoric acid (HF) to fluoridate water, although it presents other health hazards. What would be the resulting pH of a solution if you addedof HF per liter of solution? With a pKa1 of 3.6, HF may be treated as a strongacin. MM)“: 3+H=ZO $1M mm; H*+F 1 Hflir‘ looméloo0ma){1og>‘ 9’53 W“? HF 7‘ Limb—[6% wagoaa/ES z; iHF a 1w 2 nfir = ”HF : EX '0'} M fi‘l’ 1 m” 510'3We —5 Jaw: " =6W M I L- fit: ”‘03 (sax/0'5) -'—“ - PW acidic BAD .Pgr +00%. OliCd/g/ 3L A 7) (4 points) To which environmental issue does the Montreal Protocol apply? a) Acid rain b) Drinking water standards fl Global climate change 9 Ozone hole 7of7 ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern