CHM 112 Exam 1 Spring 2009 Berg

CHM 112 Exam 1 Spring 2009 Berg - CHEM 112 Exam 1 Spril1g...

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Unformatted text preview: CHEM 112 Exam 1 Spril1g 2009 Dr. Thomas Berg NAME:- - - - Total Points = 150 Questionsl-30: 5 points each 'USEFUL INFORMATION: R = 8.314 J . mor1 Kl DE=q+w 1. Which of the following statements is true? a) L\H q at constant volume and L\E = q at constant pressure. b) L\H = w at constant volume and L\E :::: w at constant pressure. c) L\E = w at constant volume and L\H = w at constant pressure. d) L\E = q at constant volume and m = q at constant pressure. e) None of these is correct. 2. What is the pH of a saturated solution of iron(III) hydroxide if the Ksp is 1.6 x 1039 ? a) 4.06 b) 4.24 c) 4.54 d) 3.94 e) None of these is correct. 3. What is the Ksp of silver oxalate if a saturated solution of Ag 2C 20 4 has a c2ol concentration of 1.41 x 10-4 M? a) 1.99 x 10-8 b) 1.12 X 10- 11 c) 4.23 d) 5.61 X X 10-4 10-12 e) None ofthese is correct. 4. Precipitation of an ionic compound will !!Q! occur upon mixing of desired reagents if the initial ion product(Qsp) is: a) greater than ~p. b) less than Ksp. c) equal to Ksp. d) Two of the above are correct. e) None of these is correct. 5. Consider the bond dissociation energies, D: Bond N-H 0=0 N=O H-O D, kJ / mol 201 498 607 467 Estimate &l for the following reaction. a) -1309 kJ b) 1309 kJ c) 3130.kJ d) -3130. kJ e) None of these is correct. 6. What is the kinetic energy of a chromium atom (8.63 x 10-26 kg) moving with a velocity of 5.50 x 103 m / s? a) 4.70 x 10-22 J b) 1.31 X 10- 18 J c) 9.49 X 10-22 J d) 2.43 X 10-22 J e) None of these is correct. 7. What is the solubility in g 1100. mL ofCaF2 in 0.10 M Ca(N03)2 if the Ksp for CaF2 is 1.5 x 1O- 10? a) 1.5 x 10-6 g 1100 mL b) 3.0 X 10-4 g 1100 mL c) 3.0 x 10-6 g 1100 mL d) 1.5 X 10-4 g 1100 mL e) None ofthese is correct. 8. Consider the following data: 2 CH4(g) + 3 Ct2(g) ~ 2 CHCe3(C) + 3 H2(g) o Lili = -118.6 kJ What is ~Ho for the reaction below? CH4(g) + 312 ce2(g) a) 59.3 kJ b) -118.6kJ c) 118.6kJ d) -59.3 kJ e) None ofthese is correct. ~ CHCt3(C) + 312 H2(g) 9. If the heat of crystallization for a particular metal is -178.3 kJ 1mol and the heat of vaporization is 337.0 kJ 1 mol, what is the heat of sublimation for the metal? a) -158.7 kJ 1 mol b) 515.3 kJ 1 mol c) 158.7 kJ 1 mol d) -515.3 kJ 1 mol e) None of these is correct. 10. How many ofthe following are state functions? heat a) 0 work internal energy volume b) 1 c) 2 d) 3 e) 4 11. What is the molar solubility of a saturated solution of iron(II) hydroxide buffered at a pH of 8.95? Ksp ofFe(OH)2 is 7.9 x 10-16 a) 5.9 x 1O-6 M b) 2.5 x 10-6 M c) 9.9 X 10-6 M d) 8.9 X 10- 11 M e) None of these is correct. 12. When 0.1 mol of solid silver nitrate is added to 1.0 L of clear, saturated solution of Ag2Cr04 (Ksp = 2.4 x 10-12), which of the following will result? a) The AgN03 will settle to the bottom without dissolving. b) The concentration of Ag+ is solution will not change. c) The concentration of CrO/- will increase. d) Some Ag 2Cr04 will precipitate. e) None of the above will happen. 13. What is the solubility in giL of silver carbonate in water at 25C if the Ksp for A~C03 is 8.4 x 10 12? a) 8.0 x 10-4 giL b) 3.5 X 10'2 giL c) 4.4 x 102 giL d) 5.6 X 102 giL e) None of these is correct. 14. What is the value of the dissociation constant, K d, for the complex ion Ni(NH3)i+? KrforNi(NH3)i+ 5.6 x 10 8 a) 2.8 x 10 1 b) 5.6 X 10.8 c) 3.5 X 10'2 d) 1.8 X 10,9 e) None of these is correct. 15. What is the molar solubility of strontium carbonate if the Ksp of SrC03 at 25C is 9.3 x 1O.10? a) 3.0 x 10.5 M b) 9.8 X 10-4 M c) 3.0 X 10-10 M d) 2.1 X 10.5 M e) None of these is correct. 16. What is the work done on the surroundings when a gas expands from 24.5 L to 45.9 L against a constant external pressure of2.50 atm? (L' atm = 101 1) a) -11.6kJ b) 5.40 kJ c) 11.6 kJ d) -5.40 kJ e) None ofthese is correct. 17. What is the most soluble salt of the following set? a) Ca(OH)2 with Ksp = 6.5 x 10-6 b) MgF2 with Ksp = 3.7 X 10-8 c) PbCf2 with Ksp = 1.7 X 10-5 d) Ag3P04with Ksp = 1.8 X 10- 18 e) CU3P04 with Ksp 6.8 x 10-12 18. Consider the following numbered processes: 1. A --t 2 B 2. B + C --t D 3. E --t 2 D bHl LlH2 LlH3 --t What is LlH for the process A + 2 C E? e) None of these is correct. 19. At 25C the Ksp for MgC03 is 4.0 X 10,5 and that for BaC03 is 8.1 x 10'9. Assuming that both Mg2+ and Ba2+ ions have 1.0 x 10,3 M concentrations, what is the equilibrium 2 concentration of carbonate ions that 'will precipitate the maximum concentration of Ba + without precipitating any Mg2+ at 25C? a) 3.5 x 10'3 M b) 4.2 X 10,3 M c) 3.2 X 10'2 M d) 4.0 X 10'2 M e) None of these is correct. 20. A solution is O.OlO_M in each ofPb(N03h, Mn(N03b and Zn(N03)2. Solid NaOH is added until the OH concentration is 3.0 x 10'6 M. Ksp for Pb(OHh is 2.8 x 10,16, Ksp for Mn(OH)2 is 4.5 x 10,1\ and Ksp for Zn(OH)2 is 4.5 x 10'17. Which ofthe following statements is true? a) No precipitate will form. b) Only Zn(OH)2 will precipitate. c) Only Mn(OHh will precipitate. d) Only Zn(OHh and Pb(OHh will precipitate. e) All three hydroxides will precipitate. 21. The heat of combustion per mol of acetylene, C2H2(g) is -1299.5 kJ I mol. Assuming that the combustion products are CO2(g) (L1HQf = -393.5 kJ I mol) and H20(C) (L1Ho r = -285.8 kJ I mol), what is the enthalpy offormation ofC2H2(g)? a) -846.1 kJ I mol b) -620.2 kJ I mol c) -226.7 kJ I mol d) 226.7 kJ I mol e) None of these is correct. 22. How much heat is absorbed I released when 45.50 g ofNH3 reacts in the presence of excess O 2 to produce NO and H 20 according to the following chemical equation? 4 NH3(g) + 02(g) -,;. a) 3.121 x 103 kJ released X b) 3.121 103 kJ absorbed c) 780.2 kJ released d) 780.2 kJ absorbed e) None of these is correct. 23. What is the molar solubility S ofFe(OH)3, in terms ofKsp for Fe(OH)3? a) S (Ksp)1/4 b) S = (KsP/4) 1/3 c) S = (KsP/27) [/4 d) S = (Ksp)1/2 e) S :: (KsP/16)I14 24. When 50.0 mL of 0.400 M Ca(N03)2 is added to 50.0 rnL of 0.800 M NaF, CaF 2 precipitates. The initial temperature of both solutions is 25.00 C. Assuming that the reaction goes to completion, and that the resulting solution has a mass of 100.00 g and a specific heat of 4.18 J I (g. K), what is the final temperature of the solution? C a 2+(aq) a) 24.45C b) 26.10 C c) 26.65C d) 27.10 C e) None of these is correct. + 2F (aq) -,;. CaF2(s) ~HO = -11.5 kJ 25. It takes 11.2 kJ of energy to raise the temperature of 145 g of benzene from 35.4 DC to 80.4 DC. What is the specific heat of benzene? a) 1.10 J I (g . K) b) 1.72 J I (g. K) c) 3.48 J I (g . K) d) 5.41 J I (g . K) e) None of these is correct. 26. How many mol of Ca(N03)2 must be added to 1.0 L of a 0.100 M HF solution to begin precipitation ofCaF2 (Ksp = 4.0 x 1O-11 )? a) 5.8 x 10-7 mol b) 1.6 x 10-9 mol c) 7.0 x 10- 11 mol d) 6.3 x 10-7 mol e) None of these is correct. 27. What is the Ksp for AgBr using the information below? Ag+(aq) AgBr(s) a) 7.6 x 10- 13 b) 5.9 X 10-8 c) 2.2 d) 2.2 X X + 2 NH3(aq) + 2 NH3(aq) -t Ag(NH3)2+Caq) + Br (aq) - Keq = 1.3 X 10-5 102 10-2 e) None of these is correct. 28. The enthalpy of formation of an element in its standard state is: a) the enthalpy of its reaction with hydrogen. b) the enthalpy of its reaction with oxygen. c) determined by its melting point. d) zero. e) None of these is correct. 29. An empty bomb calorimeter has a heat capacity of 837 J / K and contains 390. g of water (specific heat equals 4.184 J / (g. K). When a 0.105 g sample of ethylene, C 2H 4, was burned in this calorimeter, the temperature increased by 2.14 C. What is the energy of combustion for one mol of ethylene? a) -50.3 kJ / mol b) -572 kJ / mol c) -661 kJ / mol d) -1.41 x 103 kJ / mol e) None of these is correct. 30. Which ofthe following is true for a process carried out at constant pressure where q = -345 kJ and w = -135 kJ? a) flE = -480. kJ and .LlH = -345 kJ b) flE c) flE = 480. kJ and flH = 345 kJ = -210. kJ and flH = -345 kJ d) LlE = 210 kJ and flH = 345 kJ e) None of these is correct. PERIODIC CHART OF THE ELEMENTS IA ~ H 1 " VilA VIII) 1.0079 ~lilA 5 2 4.00260 IIA IvA 6 VA 7 V(A He 10 Be Li 9.01218 &.9.' 22.98977 24.305 3 4 Na Mg 11 '2 26..981539 Si P 5 CI Ar AI 28.0855 30.97376 32.066 35.453 39.948 31 10.811 12.011 14.0061 15.9994 18.99U403 20.179 14 13 16 18 17 15 B C N () 8 9 F Ne 39.09113 40.078 38 37 K Ca 44.9559 Ti Sc 41.88 39 19 20 21 22 85.4678 87.62 55 56 Rb Sr Y Zr Nb Mo .' Tc Ru (98) 88.9059 57 138~90~ 40 50.9415 51.996 54.9380 55.841 58.9332C 58.69 44 41 43 45 46 42 V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 63.546 65.39 69.723 72.61 74.9216 18.96 79.904 83.60 75 101.07 102.905f 106.42 h07.868~ 112.41 114.82 118,710 121.75 78 79 76 80 n 81 02 03 196.966~ 23 24 25 26 27 20 29 30 32 33 J.4 35 36 91.224 92.9064 95.94 74 72 73 Rh Pd Ag Cd In Sn Sb 127.60 I 131.29 Te Xe 126.'045 47 48 49 50 51 52 53 54 132.!J0$4 137.33 Cs Ba *La HI Ta W Re Os Ir 'Pt 87 (223) Fr 226.02504 227.0211 (261 ) Ra "Ac Rf Db .59 Bh Hs Mt (263) J~~21 (262) (265) (266) 88 89 178.49 180.9479 183.85 18&.207 190.2 192.22 195.09 107 108 109 104 105 106 Au ~J' 65 84 (209, 85 (21 01 204.383~ TI Pb Bi Po At 207.2 208.9604 Rn (211J 86 58 59 60 61 62 63 64 . 66 67 140,115 140.90n 144.24 90 91 Ce Pr Nd Pm SI11 Eu Gd Tb Dy Ho Er. Tm Vb (145) . 150.36 1!i1.96 151.25 168.926-4 162.50 164.9304 , ,,1.26 168.~2 68 69 70 173.04 H4.%1 j Lu 103 71 2'JZ.0J.81 231.0359 238.029 237.0482 (244) Th Pa U Np Pu Am c~ Bk Cf Es Fm Md No Lr (243) (241) (241) (251) (252, (251) 97 98 99 92 93 . 94 95 100 101 102 .. (2511) {2S9) (ZGOI 4fuJt~ 1<.04 tf ~.ke-r -b E ~ c: DL D\. .~lft1lo-d;a~; At 2()o9 =<tv- ; AJ-I=t ~ r~3 +J" . , ~ ,-~ e5') +" OJI (Of J ~ /J~J F1t41 F(!(oJ4)3 (.i') k~,o -: 1.10 >t.IO -3'1 ::: J. to X-Jlf jy :: I fe fj [uli j 3 . (~) (3.~J3 ~ .:;:l'?.s Lf S = g,t/1 X'V -II 11 .J ." A.. . [ /r~ 3 S .: t?\oog, XID --I D o Poli -" -Jif ,1, ~ ND-/D .::: 9...f8'. fJJf=- 1i 'I~ (j 3 A ;t('?o<i(.l) 3 KS(} :: ~~ ~"1) t- CzO/(~yJ J~j.l~ [c<o.fJ I, / J.. :: (.2 (/.4I'i,II/<I)Y (I. 'II XI 0-9'J := x>o -/I Q~,o .: k~,o ~ ;()t) ItI: QiIJ -< K.s,o j /JD t. H= ftl: t7I ~ 11 g i7. 0 'i t i3c p :: Id- ( /jEAJ ._J-/) S- (BE D==O) - '1(~EAJ=o)-I.,I (!jC/I-a) 1- =JJ..fhuf. 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[eli-1~ [Fj ~ ';:: (IU(J) iA .: 'o X/D . -9 M mt!(C'cAFl..:; if () XI 0-" In~ ~. 0 A-J ~ .lj~o Xlc -'f J?/uf... A ;1 ~ t4r (5) t ,UJj/j (,~) - > ~~H~)./;" f) -1-$;. f I 1:;'7 : J.a ;&o-~ KG( : 'Ikf /J Ai~\/("7J -) 1 t,,~) -t,;.9& (4~) ~ 13,,(1') ~ 17 t(4f + er-(~y, ~.<jx/o-j- 9 ~ - M ( Ctil 0 t ('1ot<l11 kJ _ _ ;: -.J,,<l<.K "o.~ Iflo ( '{./J-'/ ~ '0) t s:3'?-c J .:: -).1'1 Vc Kjp ~- kG; x ko< = ,.to XICJ -I] (/~3 -< TIDe r -3 ?-YcJc.) .:. -),/'1 Uc.. .: i1I ('(~b'j Jjod .s. ~&- XI () .3 I o C2 iI" ~ (). JOj C<!Iy "" d ( .;(f'. 0') Clff'/ J mtrf. ClIAL) - _ 3 .'7'1 x/o ;0/0( . -J llJ-i !.Jut..; _ -S:Jf)</o 3d Cuntb - ,_ 3.'/<;'1../0 -j /?/cf.. =--/.t.tl 'X/Q J/mcre (-/. t./ I XI () J kf)l?;lr( ) . A 30 ~~b "!t~~ I'XtL 3'1S k:J (e'AO MC/';111 (. f'Xl1) 1p-= .Ali := - !J.E=9t.w ~ ~::IJ,f =6I11'LU= -3 ~J J<J t (-13j- J<JJ-- - LIfo l<j CHEM 112 Exam 2 Spring 2009 Dr. Thomas Berg NAME:- - - - - Total Points = 150 Questionsl-30 : 5 points each USEFUL INFORMATION: D.G= D.GO + RT In Q k= 1.381 [(lJT2) - X 10-23 J IK In [K2/Kl] =- [LlHo IR] (1 IT l )] 6.Gt = Ln' b.Gt(p) - L m . b.Gt(R) In [k2/kl] =- [Ea/R][(l IT2)-(1 I Tl)] e-(Ea/R1) k=A R = 8.315 J I (mol- K) (1 I [ ]) = kt + (1 I [ ]0) [ ] = -kt + [ ]0 In[ ] = -kt + In[ ]0 1. What is the value of LiSouniv for the following reaction at 25 C? 2 NO(g) + 02(g) LiH.f.2 kJ I mol 33.2 90.3 0 - 2 N02(g) So~ J I (mol- J() N0 2(g) NO(g) 02(g) 239.9 210.6 205.0 a) 184.3 J I K b) 236.6 J IK c) -529.4 J / K d) -146.4 J I K e) None of these is correct. 2. Which of the following does not have a value of zero for its free energy of formation? a) Li(s) b) He(g) c) N2(g) d) F2(g) e) All have the value of zero. 3. For the hypothetical second order reaction: A products, the general rate law is rate = k [Af How long is the fourth half-life ofthe reaction if [A]o is 0.065 M and the first half-life is 10.0 min? a) 10.0 min b) 80.0 min c) 1.25 min d) 40.0 min e) None of these is correct. 4. The decomposition of ammonia to nitrogen and hydrogen on a tungsten filament at 800C is independent of the concentration of ammonia at high pressures of ammonia. What is the order of the reaction with respect to ammonia? a) zero b) fIrst c) second d) third e) Cannot be determines from the given information. 5. The following set of data was obtained by the method of initial rates for the reaction: Br03 (aq) + 5 Br (aq) + 6 H\aq) ~ 3 Br2(aq) + 3 H20(C) Expt 1 2 3 4 [BrO;! ], M 0.10 0.20 0.20 0.10 [Dr), M 0.10 0.10 0.15 - [W],M Initial Rate. M . S'l 8.0x 1.6 x 2.4 X 5.0 X 104 10-3 10'3 10'3 0.10 0.10 0.10 0.10 0.25 What is the rate law for this reaction? a) Rate = k[Br30-] [Br ] [W] b) Rate = k[Br03-f [Br-] [W] c) Rate = k[Br03 ] [Br-] [H+t d) Rate = k[Br03-] [Br-] [H+]2 e) None of these is correct. 6. If a process with a negative value of ~S is nonspontaneous at constant temperature and pressure: a) b) c) d) e) ~G ~G ~G ~G ~G is negative and is negative and ~H ~H may be positive or negative. is positive. is positive and ~H may be positive or negative. is positive and is positive and ~H ~H is positive. is negative. 7. A plot of 1/ [CeO] vs time is linear for the reaction: 3 ceo - (aq) - ceo3 (aq) - + 2 ce (aq) What is the order of the reaction 'with respect to the hypochlorite ion, CeO? a) 0 b) lh c) 1 d) 2 e) None of these is correct. 8. For the reaction: What is the Kp for this reaction at 700. K? a) 10.1 b) 16.7 c) 22.5 d) 9.90 x 10-2 e) None of these is correct. 9. Consider the reaction: t.HO = -56.8 kJ t.SO -175J IK In a container at 298 K N 20 4(g) and N02(g) are mixed with initial partial pressures of2.4 atm and 0.42 atm, respectively. Which of the follO\\'ing statements is correct? a) Some N204(g) will decompose into N02(g)' b) Some N02(g) will dimerize to form N204(g)' c) The system is at equilibrium at these initial pressures. d) The final total pressure must be known to answer this question e) None of these is correct. 10. Carbon-14, which is present in all living tissue, radioactively decays via a first order process. A 1.00 g sample of wood taken from a living tree gives a rate for carbon-14 decay of 13.6 disintegrations per min. If the half-life for carbon-14 is 5720 yr, how old is a wood sample that has a rate of carbon-14 decay of 6.30 disintegrations per min per g? a) 1.47 x 104 yr b) 6.35 c) 3.11 X 103 yr 103 yr X d) 1.23 x 103yr e) None of these is correct. 11. What fraction of collisions will have sufficient energy to react for a gas whose activation energy is 75.0 kJ I mol at 30. C? a) 3.17xlO-s b) 4.19 x 10-11 c) 1.18 X 10- 13 d) 7.40 x 10-1 e) None of these is correct. 12. The decomposition of dinitrogen pentoxide is shown in the following reaction: 2 N20s(g) ~ 4 N02(g) + 02(g) If the rate of appearance ofN02 is equal to 0.560 moll min at a particular moment, what is the rate of appearance of 02 at that moment? a) 0.140 moll min b) 0.280 moll min c) 1.12 moll min d) 3.24 moll min e) None of these is correct 13. The typical steam turbine using superheated steam at about 850 K has an efficiency of approximately in the conversion of heat to useful work (electricity). a) 10 % b) 30% c) 60 % d) 80% e) 100 % 14. The second order reaction: 2 Mn(CO)s ~ Mn2(CO)1O , has a rate constant equal to 3.0 x 109 M- l . sol at 25C. If the initial concentration of Mn(CO)s is 1.0 X 10-5 M, how long will it take for 90 % of the reactant to disappear? a) 3.3 x 10- 16 s b) 3.7 X 10-15 s c) 3.0 X 10-4 S d) 3.7 X 103 s e) None of these is correct. 15. The value ofKp is 3.14 x 10-1 at 755 K and 4.17 X 10-4 at 355 K. Assuming ~Ho for this reaction is independent of temperature over this temperature range, what is the value of ~Ho for this reaction? a) 43.1 kJ I mol b) -37.0 kJ I mol c) -43.1 kJ I mol d) 28.6 kJ I mol e) None of these is correct. 16. Consider the reaction: ~HO = 126.4 kJ I mol ~SO -74.9 J I (mol K) Which of the following statements is true for this reaction? a) Both m and ~SO favor the reaction's spontaneity. O b) Both ~Ho and ~SO oppose the reaction's spontaneity. c) ~Ho favors the reaction, but ~SO opposes it. d) ~Ho opposes the reaction, but ~so favors it. e) None of these need be true. 17. For the vaporization of benzene at 1 atm, ~Hovap normal boiling point of benzene? a) OCC b) 79.8C c) 353C d) 49.7 cC e) None ofthese is correct. 30.5 kJ I mol and ~Sovap = 86.4 J I (mol K). Assuming these values are independent of temperature, what is the 18. The experimental rate law for the decomposition of nitrous oxide (N20) to N2 and O 2 is rate = k[N20f Two mechanisms are proposed: 1. II. step 1: N 20 N2 + 0 step 2: N 20 + 0 N2 + O2 ~ ~ step 1: 2N2O step 2: N 40 2 ~ ~ N 40 2 2N2 + O2 Which of the following could be a correct mechanism? a) Mechanism I with the first step as the rate-determining step. b) Mechanism I with the second step as the rate-determining step. c) Mechanism II with the second step as the rate-determining step. d) Two of the above could be correct. e) None of the above could be correct. 19. Which combination results in a spontaneous process at a sufficiently high temperature? a) 6H is positive and 6S is negative. b) 6H is negative and 6S is positive. c) 6H is negative and 6S is negative. d) 6H is positive and 6S is positive. e). 6H is zero and 6S is negative. 20. Assume room temperature is 25 e. What is the activation energy (Ea) for a reaction that triples the reaction rate after a 10 e increase? a) 7.99 x 10-1 kJ / mol b) 47.7 kJ / mol c) 83.8 kJ / mol d) 63.7 kJ I mol e) None of these is correct. 21. What are the signs of ~H and ~S for the reaction represented in the below drawing? a) b) c) d) ~H = + and ~S = + ~H = - and ~S = + and ~S = ~H = ~H = + and ~S = e) It is impossible to determine these signs. 22. Consider the following hypothetical reaction: 2 A(g) + 3 B(g) + C(g) ~ products If the rate law is: Rate = k[Af [B]3 [C]-I, what is the overall order of the reaction? a) first b) second c) third d) fourth e) fifth 23. For the conversion of ice to water at -15C and 1 atm: a) b) c) d) ~G ~G ~G is positive and ~H is negative. is negative and ~S is negative. is negative and ~H is positive. is positive and ~s is positive. ~G e) None of these is correct. 24. Which of the following statements are true about reaction mechanisms? I A mechanism can be proven correct by experimentation. II The rate of the reaction is dependent on the slowest step in the mechanism. III A rate law generally does not include intermediates. a) I only b) I and II only c) I and III only d) II and III only e) I, II, and III 25. For the reaction 2 N20S(g) collected: time, min --+ 4 N0 2(g) + 02(g) , the following data were o 10. 20. 30. 40. 50. 70. [N~iliJ, M 1.24 x 10-2 0.92 x 10.2 0.68 X 10-2 0.50 X 10-2 0.37 X 10-2 0.28 X 10-2 0.15 X 10-2 What is the order of this reaction with respect to N 20s? a) 0 b) l;4 c) 1 d) 2 e) N one of these is correct. 26. A three-step mechanism has been suggested for the formation of carbonyl chloride(COCf2): Step 1: Ct2 - - 2 Ct Step 2: Ct + CO -- COCf Step 3: COCf + Cf2 -- COCt2 + Cf Which species is an intermediate in this mechanism? a) Ct b) CO c) COCf d) COCf2 e) None of these is an intermediate. 27. Consider the following reaction at 25C: What is the value of L\Go for the reaction? a) 102 kJ b) 50.6 kJ c) -30.3 kJ d) -50.6 kJ e) None of these is correct. 28. For a reaction that follows the general rate law, Rate:;: k[A]3 [BJ2, what will happen to the rate of reaction if the concentration of A is reduced by half and B is increased by a factor of 3? a) increases by 1.50 b) decreases by 1.12 c) increases by 1.12 d) decreases by 1.50 e) None of these is correct. 29. Which of the following processes has the correct sign for I).So? I Si02(s) + 3 C(s) II Fe(s) + 2 HBr(aq) ~ SiC(s) + 2 CO(g) FeBr2(aq) + H2(g) ~ I).So > 0 I).S > 0 ilSo < 0 0 ~ III Pb(N03)2(s) + H2 0 (t) a) I only b) III only c) I and II only d) II and III only e) I, II, and III Pb(N03h(aq) 30. Using the data below, what is the value of 1).0 for the following reaction at 500. K? ilH [(kJ I mol) CU(s) o o -241.8 -155.2 H20 (g) CuO(S) H2(g) o SO ( J I (mol' K) 33.3 188.7 43.5 130.6 a) -86.6 kJ b) 23.9 kJ c) 110.6 kJ d) -62.6 kJ e) None of these is correct. PERIODIC CHART OF THE ELEMENTS IA ~ _ - 1"r- 1.0019 , ~ VilA VillA 2 4.00260 10 IIA 3 4 rllA 5 IVA 6 VA 7 ViA He &.9.' 11 Li Be 12 9.01218 22.91971 24,305 19 20 ,39.0913 40.078 Na Mg 21 Co Ni Cu K Ca 44.9559 47.88 50.9415 51.996 Mn Fe ~8.9332( 58.69 63.546 Zn 69.723 72.61 74.9216 78.96 79.904 83.80 Sc Ti V Cr Ga Ge As Se Dr Kr 65.39 55.847 54.9380 38 39 22 23 24 25 26 27 28 29 30 26.981539 28.0855 30.97376 32,066 35.453 39.948 ,33 36 31 35 J4 32 AI Si 10.811 12.011 14.0067 15.9994 18.900403 20.119 14 16 17 13 18 15 B C N P () 8 9 F Ne 5 CI Ar 37 85.4678 87.62 55 56 Rb Sr Y 88.9059 91.224 92.9064 95.94 74 57 72 73 Pd Sn Sb Te Zr Nb Mo ' Tc Ru Rh 106.42 Ag Cd In 118.710 121.75 127.60 I Xe (98) 114.82 131.29 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 132.9054 137.33 Cs Ba *La HI Ta W 138~!I055 fUl) Fr Ra 'Ac (261) Db 59 Bh Rf fZU) (263). (262) 226.02$4 221.0211 58 59 60 '40.90n 144.24 87 88 89 178.49 180.9479 183.85 18&.207 190.2 192.22 195.09 1,96.9665 109 108 104 105 106 107 Re Os Ir 'Pt Au ~JI 204.3833 207.2 200.9004 Po At Rn TI Pb Bi (l091 (2101 (212' 75 101.07 76 102.905~ 107.868~ 'n 78 79 112.41 60 126.'045 61 62 83 84 85 06 Hs Mt (265) (266) Ce Pr Nd Pm. Sm Eu Gd Tb Dy Ho Er. Tm Yb (145) 150.36 151,96 151.25 168.926-4 162.S0 164.9304 "61.26 140,115 '64.93-42 l1l.1M 101 12~ft' 61 62 63 64 65 . 66 67 68 69 70 114.9(1 LUJ 10J 71 132.0381 Th Pa U Np Pu Am (243) lJl.0J~9 '90 91 92 9J 94 95 238.029 1J1.0482 (244) em Ok (247) (247) .96 97 96 (251) ,99 Cf Es Fm Md No Lrj (252/ (257) (159) (260) .. 100 102 e E ;( I 3 Ilak. :~Di:JL . .lh!-oJer ..fJh= AU)il J ~C7nfL. rtlJ4) ~ ~ ,,,,,= 4ft.Ld -I.///.. ~ )(),O ~ CL4e(J ~//I--J , 64 q{ 'z1IcA. -1:1/ L :::..J(), 0 /?//~ dl//c... J~ -lilt. :: .1/0.0 '-ItL b/t. .;- flJ. 0 P?/~ Gl1U JI~ ~o<J ~ 7' II i(c.b.. 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C'li'19 KJ/I(J (, .:: S--4,.bkJ' t ~3. 9 J<S =- //0,6 kJ -.l r CHEM 112 Exam 3 Spring 2009 Dr. Thomas Berg NAME:- - - - - Total Points == 150 Questionsl-30: 5 points each USEFUL INFORMATION: amp = coulomb / s Jl = 96,486 C ~ ~ = ~o _ (0.0592 V / n) log Q = ~o _ (0.0257 V) n) In Q ~x::::: -1.4 V -1.0 V 2 HzO(t) + 2 e~ ~ H 2{g) + 2 OH-(aq) + 2 e ~red::::: 2 sol-(aq) .S20g1-(aq) kWh = 3.60 x 10 J 6 1. Consider the following standard reduction potentials: Ag+(aq) + e C o3+(aq) + e ~ ~. = 0.80 V 1.82 V C0 2+(aq) ~o= What is the standard cell potential for the cell shown below, and detennine whether or not the reaction is spontaneous under standard conditions? Ag+(aq) + Co2+ (aq) a) 1.02 V b) 1.02 V c) 1.02 V d) 1.02 V nonspontaneous spontaneous nonspontaneous spontaneous ~ Ag(s) + Co 3+(aq) e) None of these is correct. 2. If the cell reaction involves ions in solution, as the cell reaction in a galvanic cell continues: a) ~ for the cell increases but ~. remains constant. b) ~ for the cell decreases but ~o remains constant. c) both ~ and ~o decrease. d) both ~ and ~. increase. e) None of these is correct. 3. A technician needs to plate 0.977 g ofCr from an Cr3+ solution. If 15.0 min is allowed for the plating, what current is needed? a) 2.01 A b) 4.17 A c) 6.04 A d) 3.50 A e) None ofthee is correct. 4. How many of the following are correct matches of sulfur and its oxidation state? Hz8 , +2 8zCtz ; +1 Liz804 , +6 88 ; 0 a) 0 b) 1 c) 2 d) 3 e) 4 5. How long must a constant current of 50.0 A be passed through an electrolytic cell containing aqueous 8nCt4 to produce 175.0 g of tin metal? a) 1.58 hr b) 19.8 hr c) 11.3 hr d) 3.16 hr e) None of these is correct. 6. \\t'hen the following half reaction is properly balanced in basic aqueous solution, what is true? Pb(OH)4 a) 1 e on the left b) 3e on the right c) 3e on the left d) 4 e on the right e) None of these is correct. r (aq) - PbOz(s} 7. For a galvanic cell that uses the following two half-reactions; AuCf4 (aq) +3 e -l> AU(s) + 4 Cf (aq) N2Hs+(aq) -l> N2(g) + 5 W(aq) + 4 e - How many mol of AuCt4 are reduced by one mol ofN2Hs+ a) 1 b) 4/3 c) 4 d) % "e) None of these is correct. 8. For a galvanic cell, the cathode has a _ _ sign and is the site of _ _ a) negative b) negative c) positive d) positive oxidation reduction reduction oxidation e) neutral , reduction 9. What is the shorthand notation that represents the galvanic cell shown below? 3 Sl1{s) + 2 Au a) Sl1{s) b) c) d) 3 \aq) -l> 2 3 Sn \aq) + 2 AU(s) I Au3\aq) II Sn2\aq) I Au(s) 2 3 Sn(s) I Sn +(aq) II Au \aq) I AU(s) 3 2 Sl1{s) I Sn \aq) I Au(s) I Au +(aq) 2 3 Au +(aq) I Au(s) II Sn(s) I Sn +(aq) e) None of these is correct. 10. Consider the half cell reaction: Which of the following changes to the half cell would increase the oxidizing power (increase the reduction potential) ofV02+? I increase the concentration ofV02+ II increase the pH III decrease the concentration ofV02+ a) I only b) II only c) III only d) I and III only e) I, II, and III 1l. What is least easily oxidized? a) At: b) Fe c) Mg d) Zn e) All are equally oxidized. 12. Which of the following is not a correct match. ofthe reactant molecule and its identity? a) Bi(OH)3 b) Mn04 ~ Bi , reducing agent Mn02 Ct:03 oxidizing agent reducing agent - ~ ~ c) HOCt: e) Two of the above are not correct matches. 13. Which of the following tenns can be used to describe an electrochemical cell in which a spontaneous chemical reaction generates an electrical current? I an electrolytic cell II a fuel cell III a voltaic cell a) I only b) II only c) III only d) I and II only e) II and III only 14. When the following reaction is properly balanced in acidic aqueous solution, what is the coefficient in front of water? Cli(s) + N03 (aq) --'" NO(g) + C 2+ U (aq) a) 0 b) 2 c) 3 d) 4 e) 6 15. When a cell reaches equilibrium: a) b) ~ O. ~=O. c) both ~ and~ O. d) neither ~ nor ~. =0. e) None of these is correct. 16. Consider the cell made from the two half reactions below: A u3+(aq, 0.050 M) + 3 e--l> All(s) ~. = ~. = 1.50 V 1.50 V Au3+(aq, 2.583 M) + 3 e What is the cell potential, ~? a) 0.03 V b) 0.20 V c) 0.10 V d) 0.14 V e) None of these is correct. 17. Consider the following cell: Pb(s) IPb2 \aq, 1.0 M) II 2 H+(aq,?} I H2(g, 1.0 atm) I P!(s) lfthe cell potential,~, is 0.03 V, what is the pH of the unknown solution? a) 1.69 b) 3.38 c) 6.08 d) 3.04 e) None of these is correct. 18. How many moles of electrons, n, are transferred in the following redox reaction? a) 2 b) 3 c) 6 d) 8 e) 10 19. Consider the reaction: Au3+(aQ) + 3 V0 2+(aq) + 3 H20([) -- All{s) + 3 V02 \aq) + 6 W(aQ) If the standard free energy is -148 kJ I mol, what is ~o for a standard cell based on this reaction? a) 1.53 V b) 1.17 V c) 0.767 V d) 0.383 V e) None of these is correct. 20_ What is the relationship between the standard cell potential, ~o, for the following two galvanic cell reactions? I II 2 Ce4\aq) + Pb(s) + SO/-(aq) 4 -- 2 Ce3+(aq) + PbS04(s) -- 4 Ce +(aQ) + 2 Pb(s) + 2 S042-(aq) 4 Ce3+(aq) + 2 PbS0 4(s) a) ~.(I) = ((II) b) ~O(I) = -~.(II) c) ~.(I) = YS ~(II) d) ~.(I) = -YS ~\II) e) ~.(I) = 2 ~(II) 21. Electrolysis of a molten salt with a formula MCt4 required 6 min and 35 s for a current of 4.00 amp to plate 0.373 g of the metal. What is the identity of the metal? a) Pt b) Zr c) Ti d) Sn e) Pb 22. What is the equilibrium constant, K, for the galvanic cell formed from the following half-reactions at 25 'C? PtCC4 2- (aq) + 2e ---l- P1(s) + 4 CC Nics) (aq) ~'= ~'= 0.76 V -0.23 V N2~ 1 (aq) + 2 e ---l a) 9.0 x 108 b) 2.8 X 1033 c) 8.0x 1017 d) 5.3 X 10 16 e) None of these is correct. 23. When the following half reaction is properly balanced in acidic aqueous solution, what is true? N 2(g) - ---l NH/(aq) a) 4 e on the left b) 6 e on the left c) 5 e on the right d) 3 e on the right e) None of these is correct. - - - 24. How many grams of chromium metal are plated out when a constant current of 7.15 A is passed through an aqueous solution of Cr2(S04)3 for 105 min? a) 24.3 g b) 14.7 g c) 8.09 g d) 12.1 g e) None of these is correct. 25. What is the standard potential, ~', for the galvanic cell composed of the following half-reactions? Sn4+(aq) + 2 eCr 3-'(aq) + 3e - a) 0.88 V b) -0.58 V c) -0.88 V d) 0.58 V - - Sn2+(aq) Cr(s) ~. 0.15 V -0.73 V ~'= e) None of these is correct. 26. Consider the half-reaction: 2 H20([) + 2e - The formation ofH2(g) occurs most readily when the solution is: a) acidic. b) basic. c) neutral. d) The reaction is not dependent upon pH. e) None of these is correct. - H2(g) + 20H (aq) - 27. What is the number of kilowatt-hours of electricity required to produce 10.0 kg of lanthanum (La) from molten LaCt3 if the applied voltage is 7.00 V. Assume 100 % efficiency. a) 11.7 kWh b) 13.5 kWh c) 9.73 kWh d) 5.79 kWh e) None of these is correct. 28. The standard potential for the following galvanic cell is 2.75 V: - Mn04 (aq) + 2 H20(c) + M(s) - Mn0 2(s) + 4 OH (aq) + M 3 \aq) What is the standard reduction potential for the M 3+ / M half cell? a) -2.16 V b) -3.34 V c) 2.16V d) 3.34 V e) None of these is correct. 29. When the following reaction is properly balanced in basic aqueous solution, what is the coefficient in front of water? - I (aq) + Mn04 (aq) - - Mn0 2(s) + 103 (aq) a) 1 b) 2 c) 3 d) 4 e) 5 30. What is the cell potential, ~, at 25 C for the following reaction, 3 Au \aq) + Mn02(s) + 4 OH-(aq) - All(s) + Mn04-(aq) + 2 H 20(t) where [Au3+] = 0.355 M, [OH-] = 0.010 M, and [Mn04-] = 0.750 M? a) 0.96 V b) 0.75 V c) 1.07V d) 0.91 V e) None of these is correct. Standard Eleetrotle (Half-ceU) Potentials (298 K)* HALF-REACTION F2 (9) O:;(.~O + 2e- ~ 2F-(aq) ~ Co2+(aq) + 2H+(aq) + 2e- ~ 02(9) + H 2 0(l) Co3+(aq) + e- H 20 2 (aq) + 2H+(aq) + 2e- ~ 2H 2 0(l) Pb0 2 (s) + 4H+(aq) + SO/-(aq) + 2e- ~ PbS0 4 (s) + 2H 2 0(/) Ce4 +(aq) Au 3 +(aq) + e- ~ Ce 3 +(aq) Mn0 4 -(aq) + 8H+(aq) + 5e- ~ Mn2+(aq) + 4H 2 0(l) C12 (9) + 3e+ 2e- ~ ~ Au(s) 2Cl-(aq) ~ Mn2+(aq) Cc 20,2-(aq) + 14H+(aq) + 6e- ~ 2Cr3+(aq) + 7H 2 0(l) Mn0 2 (s) + 4H+(aq) + 2e- + 2H 2 0(l) 02(9) + 4H+(aq) + 4e- ~ 2H 2 0(l) Br 2 (l) + 2e- ~ 2Br-(aq) NO:; -(aq) + 4H+(aq) + 3e- ~ NO(9) + 2H 2 0(l) 2Hg2+(aq) + 2e- ~ Hg/+(aq) Hg2 2+(aq) + 2e- ~ 2Hg(/) + e- ~ Ag(s) Fe3+(aq) + e- ~ Fe2+(aq) Ag+(aq) 02(9) + 2H+(aq) + 2e- ~ H 0 2 (aq) 2 ~ Mn0 4 -(aq) + 2H 2 0(/) + 3e- I 2 (s) + 2e- Mn0 2(S) + 40H-(aq) ~ 2r (aq) 02(9) + 2H 2 o(/) Cu2+(aq) + 2e- + 4e~ ~ 40H-(aq) Cu(s) AgCl(s) + e- ~ Ag(s) + CI-(aq) SO/-(aq) + 4H+(aq) + 2e- ~ S02(9) + 2H2 0(l) Cu2+(aq) + e- ~ Cu+(aq) Sn4+(aq) + 2e- ~ Sn2+(aq) 2H+(aq) Pb2+(aq) +2.87 +2.07 +1.82 +1.77 +1.70 +1.61 + 1.51 +1.50 +1.36 +1.33 +1.23 +1.23 +1.07 +0.96 +0.92 +0.85 +0.80 +0.77 +0.68 +0.59 +0.53 +0.40 +0.34 +0.22 +0.20 +0.15 +0.13 0.00 + 2e- ~ H 2 (g) + 2e- ~ Pb(s) Sn2+(aq) + 2e- ~ Sn(s) N2 (9) + 5H+(aq) + 4e- ~ N2HS +(aq) Ni2+ (aq) + 2e- ~ Ni(s) Co2+(aq) + 2e+ 2e- ~ Cots) ~ PbS0 4 (s) + 2eCd2+(aq) Pb(s) + SO/-(aq) ~ Cd(s) Fe2+(aq) + 2e- ~ Fe(s) Cr3+ (aq) + 3e- ~ Cr(s) Zn2+(aq) + 2e- ~ Zn(s) 2H2 0(l) + 2e- ~ H2 (g) + 20H-(aq) Mn2+(aq) + 2e- ~ Mn(s) AP+(aq) + 3e- ~ Al(s) Mg2+(aq) + 2e- ~ Mg(s) Na+(aq) Ca2 + (aq) -0.13 -0.14 -0.23 -0.25 -0.28 -0.31 -0.40 -0.44 -0.74 -0.76 -0.83 -1.18 -1.66 -2.37 -2.71 -2.87 -2.89 -2.90 -2.93 -3.05 + e- ~ Na(s) Sr2+(aq) Ba2+(aq) K+(aq) U+(aq) + 2e+ 2e- ~ Cars) ~ Sr(s) + 2e~ ~ Ba(s) + e+ e- ~ K(s) U(s) Written as reductions: 0 value refers to all components in their standard states: 1 M for dissolved species; 1 atm pressure for gases; the pure substance for solids and liquids. PERIODrc CHART OF THE ELEMENTS IA I~ 3 6.941 4 IIA 22 - 1 ...... H 1.0019 vilA lilA 5 IvA 6 VA 7 --~ VI:A - VIII) 2 4.00260 He 10 Li 9.01218 Be 11 12 Na Mg U.98911 24.305 2081539 28.0855 30.97376 32.066 35.453 39.948 21 AI Si P 31 32 .33 72.61 10.811 12.011 14.0067 15.9994 18,996403 20.171 14 17 16 18 13 15 B C N () 8 9 F Ne 5 34 CI Ar 35 36 39.0983 40.078 44.9559 47.88 38 39 40 I 37 K Ca Sc Ti '9 20 85.4678 87.62 56 55 Rb Sr Y .. (22~! Pb Bi At Re Os Ir 'Pt Au ~.~ TI 207.2 206.9604 Po (ZIO, Rn (Z09) 132.9054 (Wl' 87 88 89 Fr Ra 221.0271 (261 ) Db 59 Bh Hs Mt 'Ac Rf (262) (265) (266) (ZU) fz&2) Cs Ba *La HI Ta W 137.33 lJa~90S5 Z2fi.02~ 88.9059 91.224 92.9064 95.94 57 72 74 73 Zr Nb Mo ' Tc Ru (98) 75 50.9415 51.996 54.9380 55.847 59.9332( 58.69 44 43 45 46 41 42 V Cr Mn Fe Co Ni Cu Zn Ga 23 24 25 26 27 20 29 30 101.07 102.905f 106.42 h07.868~ 112.41 114.82 118.710 121.75 70 79 76 80 01 n 02 83 204.383~ Rh Te Pd Ag Cd In Sn Sb 127.60 84 63.546 47 65.39 48 69.723 49 Ge 74.9216 78.96 As Se 50 51 52 79.904 83.00 53 54 Br Kr I 131.29 Xe 86 26.'045 85 178.49 180.9479 183.85 18'.207 190~2 192.22 195.09 1.96.966f 109 108 104 105 106 107 ~ 59 60 61 62 63 64 65 . 66 67 68 69 70 71 f14.9U 103 140.115140.90n 144.24 91 Ce Pr Nd PmSm Eu Gd Tb Dy Ho. Er, Tm Yb Lu (145)' 150.36 93 94 15'-96 ,.151.25 168.9264 J62.5U(;4.9304 .161.2& '63.~2 173.04 roo Pa U Np Pu Am em Ok Cf Es Fm Md No Lr, (247) (247) (243) (251, (2521 (251) 131.0481 (244) (259) (260, j 92 95 2JT.~ .96 97 96 99 100 101 102 ,~J~ 238.02' .(25ft) c I c 3 HzS ~ -~ <;,'1 .., t<l$) ~f..l.S()4: +Ic S~ (Qt : t i S ~ ~ 0 +4e~ -), S/l(~!AJ a s~1).:-:-(_~d/l S)I'f( ~,:~[~). S'.-r {'ilJe(hr) = /')j 'oai'i i 1k. 1 ,-is )( ( Sa.o c. 3~oOJ -= 3./1.0 r/1'l 1d/I!fSIj 'br-_) 1 Pb( <llt)'1~) -) PbO~u\ (~t'( CAy) Pb(oI-fL,~~)-) P);tJk)+-.).~ <}tJ+ ~e 'i( AlA..~"-~f) dci" -) Au-(n t <I (t(cq) ) hr ~ ( vA HSt(o.,) -) J),),({j) t S H;'t1 ,.. 'I d J3 I( A I~ E 13 ~ pI 3 C'<.\(.1) + J IlJOj ~~) - ) ~ ,(J()() r 3 (c.c. ((41 j c1to-<..t-; - ~ -) + (, ; c..cJJ. S- " tOIl .R.,JI ~J. "lll.o GlJ1 " <7 r'j:ht ., -; &' 14 ~'t) t ('u.(.1l ;-J..,a,3~~7) -"> ;u.J()(~) t 3 (u...1,~4~) ~ Vll) Ph(5) + ~ H (<-\7) ,1 -;> Pia ~~' (uC{) + ~ (J) CO :: 0,/6 ?evi II i),o3v = 0./3 V _ O,W).o -'9S ? .OJJ!'k'Q"d (t;.p) (-~j~(H~J) /' v .0 -o~t()V = 70.('f~ \I (Ilfl) pH,;:; -:Ofq~ v = ,-O.IOV I (g-ul C If> :n.\) Jf~u R~ IF -- g~ PI: CR", (6.y ) 1-,;( e - ) Pt:(!) .v ~ l ~ ) - ) JfJ ~ ~~y) +~ e - 2,- - t J../ (12. (Vlj) f~x:- 0,;)6/ fc~// -~ 6. 99v It ;)J ~j ;:; O,lJ"v 0, -131/ fay. -. Sn (4f) 6 41t . r ~'1!j - ) f 3.)1t :J.t (47) + ~ C"'(J} . J1 0(RJ t.?c:- - ) 1-/<11-) ~tOIf~f) --) GtliU~ R.O<i ~-- II E J1 t 'I ()j'k~ 9) f,J ;: O.~r9' V f:v.: ? kel/:J//fV J11."O'-l(~) -;.P!U)t ;2.1~(O(l) . .... 3f -)I!(tAC;} f-~O~(.\J1- ~O/fp7) -." f(}lj. .... , _ o ~ ,(.1fV - D, ..r~ := V: :?/b V I-c{ +.1~_ f:e~~ 11... -)~J6V 1(4)) r tJ1JlO'/C<3Jf) I 1 \ If be" ; .;t 13e:.' : ; ~ I ~~d ~ - ) fJ/nOJ..(s.) + ID3 (Et,) I I. (~7) t :l!l/h()'1- - ) ..z 10/,,0.11 J) +I03~"j ) cho..rqe.,' -.3 -) -, ; 4J~ ~ t.u( O)t c:lJ~ l-IlO C11 rtjlt f: ffeff U)}j Ii O(-l} + I ./J Jj ~~) t ).11/11 30 11u..... (~~) 1 )'1ft! OJ.(~) A 3+ 3e. - O'l-~';) -) .;{ 111{()~ uJ f- IOJ ;"7J t A S"0 -) '-'lJ) I ~vt .' I.Ja LI ;qy J + '1OJ1~~J -) //IIO'l-C9f) -r1.I-'lOrJ.) r3e - k: -O.F9 LJ ~~/." 6.9ft! o A}~~) ; t /lfIlOd,(S) t Lj 0)( bO (J fAJ'! [0Jf-!" -) Ava) >t 11/111)1./~~7 J +o2 ~ <J (.Q.J .:- 0,"1 J IJ .. ' o.Ffo? V j (_j/"110~-J ) -3 f"- , _. OJj..< 1I 0.'711) . _3 .Q'd- ( : 1 JO -1 3D- (OIOJ 4) ;; () .7'J V .... "O~J. 1/ (8-.32 ) -= 0 .<flll - (J .Ib V .:: o.1f V CHEM 112 Exam 4 Spring 2009 Dr. Thomas Berg NAME:- - - - - Total Points == 150 Questionsl-30: 5 points each USEFULINFO~TION: nm=10-9 m e = 2.998 x 108 m's-1 ao::: 0.529 A me = 9.109 x 10-31 kg mp = 1.673 x 1027 h ::: 6.626 X 10- Js 34 J = kgom 's = . 2 2 kg Ry 2.180 X 10-18 J e = 1.602 X 10-19 C NA = 6.022 X 1023 mor1 6.(position) 6.(velocity) > h I ( 41tm ) A.::: he I eVthr A. = hI (2meV)'I. A.::: h I mv En::: _Z2 I n 2 (Ry) 1. \\That is the wavelength of an ultrasonic wave of frequency = 5.00 x 104 Hz that is propagating through a sample of water at a speed of 1.53 x 103 m / s? a) 5.00 x 103 m b) 32.7m c) 11.7cm d) 3.06 cm e) None of these is correct. 2. In 1905, Albert Einstein brought together the work of which two scientists to explain the photoelectric effect? a) Henrich Hertz and Neils Bohr b) Henrich Hertz and Max Plank c) Max Plank and Neils Bohr d) Max Plank and James Franck e) James Franck and Gustav Hertz 3. How many electrons can be described by the quantum numbers n = 4, t = 3, mE = 1, and ms = 1? a) 0 b) 2 c) 6 d) 1 e) None of these is correct. 4. What is the general trend in ionization energy and affinity (most negative) values? a) Both decrease as one traverses a period from left to right and both decrease as one descends a group. b) Both decrease as one traverses a period from left to right and both increase as one descends a group. c) Both increases as one traverse a period from left to right and both decrease as one descends a group. d) Both increase as one traverses a period from left to right and both increase as one descends a group. e) None ofthese is correct. 5. Suppose photons of green light (A = 5.30 x 10.7 m) are used to locate the position of a baseball of 149 g to an accuracy of one wavelength. What is the minimum uncertainity in the speed of this baseball? a) 6.68 x 10-28 m / s b) 9.95 X 10-29 m / s c) 6.68 X 10-31 m / s d) 9.95 X 10-32 m / s e) None of these is correct. 6. For the hydrogen atom, which electronic transition would result in the emission of a photon with the least energy? a) 3s ---+ 2s b) 8i---+4f c) 4p ---+ 3s d) 5f---+4d e) 5f ---+ 3p 7. Consider an atom traveling at 1.00 % ofthe speed oflight. The de Broglie wavelength is found to be 3.31 x 10.3 pm. Which element is this? (pm = 1012m) a) He b) Ca c) F d) Be e) P 8. What is the second Bohr radius of a Li2+ ion? a) 0.705 A b) 1.06 A c) 0.353 d) 0.118 A A e) None of these is correct. 9. What is the kinetic energy of an electron emitted from a metal surface with a threshold frequency of 5.38 x 10 14 Hz using a photon frequency of 2.67 x 10 15 Hz? a) 2.12 x 10. 18 J b) 3.56 X 10. 19 J c) 7.69 X 10-19 J d) 1.41 x 10. 18 J e) None ofthese is correct. 10. Which of the following most clearly supports the fact that electromagnetic radiation has wave characteristics? a) emission spectrum of hydrogen b) the photoelectric effect c) scattering of alpha particles by metal foil d) diffraction e) blackbody radiation 11. What is the wavelength of the line spectrum corresponding to the transition from n = 7 to n = 4 for He+ ion? a) 2166 run b) 541.5 run c) 274.9 run d) 789.3 run e) None of these is correct. 12. Which of the following quantum number describes the orientation of an orbital? a) principle quantum number b) spin quantum number c) magnetic quantum number d) Schrodinger quantum number e) angular momentum quantum number 13. Which of the third shell orbitals shown below is 3dyz z (a) z (b) z 14. In which orbital below would an electron (on average) be farthest from the nucleus? a) 2s b) 4f c) 3d d) 3p e) 5s 15. Which atom in each group (1 and II) has the largest atomic radius? I Sr, Sn, I a) Sr b) Sr N As II N, P, As c) 1 ;N d) Sn , As e) None of these is correct. 16. What is the first shell in which an i orbital would be allowed? a) fifth b) sixth c) seventh d) eight e) i orbitals are impossible. 17. In the quantum mechanical description of an electron, what is the physical significance of the square of the wave function, qr2? a) determination of the electron's subshell b) exact position of the electron c) probability of the electron's energy d) probability of the electron's position e) None of these is COlTect. 18. Which groups of elements, indicated by letter on the periodic table, have two unpaired p electrons in their in their valence shell in the ground state? IIIIIII11111111 a) B only b) A and B only c) A and Conly d) B and Conly e) Band D only 19. Which form of electromagnetic radiation has the longest wavelength? a) y-rays b) microwaves c) radio waves d) IR e) X-rays 20. Which has the greatest Zeff for its valence electrons? a) Na b) K c) Si d) C e) P 21. Which of the following represents electron configurations that violate Hund' s rule? 1 2 I [Ne] 3s 13p/3p/3pz 4s II [Ar] 4s23dx./3dyz13dxz14P/ III [Kr] 4dlOSPxlSp/Spz2 a) I only b) II only c) III only d) I and II only e) II and III only 22. Modern Quantum Theory is based on the uncertainty principle, which was first stated by which scientist? a) Max Plank b) Albert Einstein c) Werner Heisenberg d) Neils Bohr e) None of these is correct. 23. Which of the following electronic configurations corresponds to an atom in an excited state? a) ls22s32p4 b) 1s22s~p62ds c) lS22hp43s 1 d) ls22s22p63s23p64s23ds e) 1~2hp63s1 24. Which of the following matches are not correct? !! ! -1 2 2 1 !!!! -1 +1 +2 -2 Comment .., a) -' b) 3 c) 7 d) 4 forbidden allowed allowed forbidden e) All of the above are correct. 25. What is the ground state electron configuration of Osmium(Os)? 2 a) [Xe] 6s 5d6 b) [Xe] 4fJ3 5d6 c) [Xe] 4f13Sd66s2 d) [Xe] 4f145d66s2 e) None of these is correct. 26. How many electrons can a single shell hold? a) 2 b) 2n c) 2n + 2 d) 2n2 e) None of these is correct. 27. A stellar object is emitting radiation at 3.55 nm. If the detector is capturing 8 3.2 x J 0 photons per second at this wavelength, what 1S the total energy of the photons detected in one hour? 13 a) 6.39 x 10- J / hr 17 b) 6.39 X 10- J / hr 6 c) 1.79 X 10- J / hr 9 d) 1.79 X 10- J / hr e) None of these is correct. 28. How many electrons in an atom may have the quantum numbers n = 3 and =2? a) 0 b) 2 c) 6 d) 10 e) None of these is correct. 29. List all the elements that have a ground state configuration with five unpaired electrtons in the 3d subshell. a) Mn, Fe, and Co b) CrandMn c) Crand Fe d) Mn e) Cr 30. What is the number ofspherical nodes in a 4s orbital? a) zero b) one c) two d) three e) four PERro'DIG CHART OF THE ELEMENTS JA ~ / 1 1,0019 H ...-. VilA Vilit ~ lilA 5 - 2 4.00260 IIA 3 1.941 11 4 9.01218 12 IVA 6 VA 7 V(A He 10 Li Be 22.98977 24.305 19 20 Na Mg 39.0983 40.078 Sc Ti K Ca 44.9559 47.88 38 56 39 21 22 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.4678 87.62 88.9059 91.224 92.9064 95.94 ' (98) 101.07 102.905f 106.42 112.41 114.82 118.710 121.75 127.60 26.'045 131.29 ~07,868~ ~ 31 40 50.9415 51.996 54.9380 55.847 58.9332e 58.69 41 44 45 42 43 46 V Cr Mn Fe Co Hi Cu Zn Ga Ge As Se Br Kr 65.39 69.723 79.904 83.80 63.546 72.61 23 24 25 26 27 28 29 30 26.981539 28.0855 30.91316 32.066 35.453 39.948 36 31 33 J.4 35 32 49 AI Si P 10.811 12.011 14.0067 15.9994 18.99U403 20.119 14 18 13 15 16 17 B C N () 8 9 F Ne 5 CI Ar 47 48 50 74.9216 78.96 51 52 53 54 132.!J054 137.33 HI Ta W Re Ir Au Cs Ba *La 118.49 180,9419 183.85 18'.207 Os 192.22 'Pt ~.96.9665 fo!Jl 204.3833 207.2 200.9804 Po (210) Rn TI Pb Bi At 190.2 195.09 (222) (Z09) lJ1~9055 55 51 72 73 14 75 76 T7 18 79 80 81 82 83 84 85 86 87 (2ZJ) Fr 22fi.02~ Ra lAc Rf Db 59 Bh Hs Mt 221.0211 (261) 1262) (263) (262) (265) (266) 88 89 104 105 106 107 108 109 140,115 ,140.90n 144.24 Ce Pr Nd Pm. Sm (145, 150.36 58 59 60 61 62 151.96 ~1.25 168.9264 162.50 164.9304 Eu 63 64 Gd Tb Dy Ho Er. Tm ,.161 26 100 16f.~2 65 . 66 67 68 69 173.04 t74.97 t02 (159) Vb 70 71 Lu 103 90 91 92 93' 94 (244) 95".96 (243) (247) 97 (247) 98 99 lOt ~1 2J!.OJ59 2J8.02!. lJl.()4111 Th Pa U Np Pu Am"m Ok Cf Es FmMd No Lrj (l~lL _ f252J ~.!II) (Z60) b <7 E~ ~ h))- h'V() .: A( - <) ) " (".1,2.1" i</o- Nl'...! &.1,'1 "'0 'J~ -I - S.YNIJ '''..J ") .:: I. ifl x/o -/~r (:;./79 XID'~/cfJ) - ) . /J.?jV ....Iq ~ .:: _;..,Ff(J[) x/c; J b. 10 e it En l:" ~l. II). E1 -- _;2 A. -;;:;: (J..J1~ X/a -/d-J l.. r::. "I- - - ~ (), .11"1 x/o- <fJ l ' .: . .r. 't 'Iq- x /0"''1-.[ (.2. 9<tJx/tJ '1t71?1.J) 6 :: I f. 4 -11 ~ 3 :~~~1 x,u'-I't J <:) he I.l E ~), ( A ;:::) :L:= /). E = .~ ~.f:16X/l;J'I:S oj 5'-1 /. {" 11/J{ 3'~k>J'1 x/o-1tfJ C C 1;;Z 13 e 1,-/ r.i'" > r 5:/f > ,.L , AGwtc ~~ ~-P-<7~1->4?. A o..J I ~~F'~J, r ;.(..1) r P .) r J(} . .4 (lA1(t ~ L-~ul. u. i l./}-t..<~ ,J01..<4f o..~.rt~ -) e:: 0 $... -sJ.r#~/~ ~ 4~ fl.: 0, II 2. . 4-; , t.40 tf~ /~J.-t# J~ D /1 f J~ r3: 1. ~ _ J b: 1!:: 11 Cv,);b itfJ4IU 1.<t{J # -- c h '9 )"0 E. j) t') ).1 )f f :: h(~) ~" E :<1 ~ .= ".(,20 )(10 - j if J'.J (.:(, 'I <tj- )( IC/'1/1Q;'J-j 3.S..r nIfL S~.s7'6 XIV ~/'l Y/ u kt /4 E (J"!hr) 12. ::- J. =:) "",5 S\ x 10-1'1:r/fltdlb?/ (3.~ Xt(j 8-~.kt/S ) ( ':;) :;;: 1.0;1 x 10 ._(, r /A r l.' '3 J J ) J. Subs ie// j Cr: r?/11; LAr.] "IJ' 3d J- !A(I ~ b 36 AI s -:) //.= J/' ,Q.::-o 7f. "'6 o/~ /l{uJ,f2-<l I\. tt-a-J t .-J . 1 l..4> 11 - j( - I = '1- () -I :: 3 ...
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