105bs10_w_sample_final

105bs10_w_sample_final - ,... scime Feb? Aoogaooq)...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

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

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

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

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

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

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

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

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

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

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11

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

View Full DocumentRight Arrow Icon
Background image of page 12
Background image of page 13

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

View Full DocumentRight Arrow Icon
Background image of page 14
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ,... scime Feb? Aoogaooq) Chemistry IOSbL First Letter of PLEASE PRINT YOUR NANIE IN BLOCK LETTERS _ 10:00 am. Section Last Name Spring 2005 Name: FINAL EXAM May 4, 2005 Last 4 Digits SID #: Professor Arieh Warshel Lab T.A.'s Name: Lab Day and Time: m “‘“M QUESTION MAXHVIUM SCORE POINTS GRADE Please Sign Below: I certify that I have observed all the rules of Academic Integrity while taking this examination. N N N N N N N N Signature TOTAL 200 INSTRUCTIONS: 1. There are 10 problems on 14 pages in this exam. Please check to see that you have a complete exam. . Please show all ofyour work to receive fiill credit. 2 3. You must use ink. Do not use a pencil. 4 . Letter grades will be available on OASIS only‘ Check OASIS afier May 20, 2005. (They will not be posted.) 5. The final course scores will be posted on the class website by 12 noon, May 5, 2005. Final exams may be viewed 10 am-12 noon, 2-4 pm on Mon, May 9; Tues, May 10; Wed, May 11 only. Sign-up for a 10 minute exam viewing on the sheet outside of SGM 220. K -. L -'. 9.x». UsefiJl Physical Constants and Equations: Avogadro's number N = 6.022 x 1023 mol‘l Universal gas constant R = 0.08206 L atm K" mol‘I = 8.314 I K" mol" Faraday's constant F = 96,485 C mol'I R KP=KC(RT)A” Kazx; ——b Jb2—4 Ifax2+bx+c=0thenx= i ac 2a PV = nRT -w = qé l amu = 9.35 x 108 eV/molecule AS=k In W c=3.00x10‘m/s AG = -nF E, 1 g = 6.021(1023 amu AG = AGO + RT an for first order reactions, AG = AH - TAS M=Moe"“,tm = 9%; E=q+w 5:50—5:an AGO =—RTaneq i=§°~fl¥3 ogloQ keq = e—AGo/RT £0 = 0.0592 logloKeq E = 110 = mc2 AGUd) = —96.5n§ (volt) -973 = _% + AS Keg : longoxoosm volts 5, Half Reactions 0.34 -O.76 —O.28 -1.03 -O.40 1.51 0.80 1.36 2.87 471 -O.13 Cu+2 + 28‘ -—> Cu(s) Zn*z+2e‘ —-) Zn(s) NV2 + 2e‘ ~> Ni(s) Mg+2 + 2c“ —~) Mg(s) Cd“z —> Cd(s) + 26‘ Mno; + 8H* + 5e‘—> Mn2*+4H70 Ag+ + e‘ —) Ag(s) C11 + 2c“ —> 20‘ F2 + 2e‘ —> 21" Na” + e‘ —) Na(s) Pb“2 + 2e‘—> Pb(s) ~0.04 Fe3+ + 3e‘ —_> Fe 1. (20 points) (a) (b) For the reaction 2N0 (g) + Br2 (g) ——) 2NOBr (g) the rate law is _ Afo}] At =k[NO]2[Br2]. What will be the change in the initial rate of consumption of Br2 if the initial amount of NO is tripled? 2 RAW ©< Emmi 8057'; - ’ Ci For a reaction in which A and B react to form C, the following initial rate data were obtained: [A] [B1 (mol/L) mol/L 0.2 0.2 0.4 0.2 0.8 0.2 0.2 0.4 0.2 0.8 Find the rate law for this reaction. Initial Rate of Formation of C (moi/Ls! 0.50 2.00 8.00 1.00 2.00 H Qefi= K [film [.ng voltmeter 2. (20 points) Consider the following cell: The Standard potential for Pb2+ and Nizi are ~O.13 V and -Ot28 V, respectively. (a) What is the value ofE° for this cell at 25° C? Write the balance equation for the overall reaction. , 2+ 2+ , ' Pb 4— Wk“) 9 PER) + N“ O E:—O,i1+o.2.8 = Ovigv (b) Which substance will be oxidized? Qt H N (Q (C) What will be the potential of the above cell when the concentration of Pb2+ IS 1 O M r. and that ofNi“ is WM? lo’g _. CM“) (— E c: __ ' IO M - (YEN matinee) Lt O,ZCi\/ OWSJ“ (ZMAQE-)<9(‘,W§Q/MJG') ’0 M (d) What will be the potential ofthe cell ifthe temperature 15 dropped to zero? {imam {A it (WAC/Mi) O A Q ,— E: i: ——T who): E a.“ 1-4 3. (20 points) Solution of [Co(NH3)fi]3+ are yellow in color, which means they absorb in the violet region of the spectrum. On the other hand, solutions of trans [Co(NH3)4Clz]‘ are green since they absorb in the red region of the spectrum. (a) Please explain this result in terms of the crystal field splitting energy A0. \nwwc smart-w RCH €371\ \) INC/LU swco Em/acv —-——> + + C 77% A0 Fit/L Rahal? IS GMAT/Lind A0 [goon/21‘ 542:] ngi an H) chn Tb "W? $34K! 39 claw”? Assam? “J. H ’ l/ A540 uuoom’riwssg m Medea w 8mm WM) am Puma/03 (b) Consider the two octahedral complexes [Co(Cl)6]+ and [Co(CN)6]+ where the crystal field splitting energy A0 is 0.5 kcal/mol for the Cl“ complex and 6 kcal/mol f0 @ CN-) +k€ complex. The electron pairing energy, P, is 2 kcal/mol for both complexes. I etermine which ofthe complexes is in the high-spin and which is in the low-spin configuration. (Hint: Co2+ is d7.) 4* ’4- ‘ Q A.” .4)? 4% 'Jr l-Houfiwd 4% 4% 1J7 LON SP‘A) C551 (if: Z(oy§)’+z<&):5 [J Cégg J : O.§+ 30—}: QYKc Cage Cu”: 2 (63+ 1(2): Maggi CF33 Cd’ 2 (0-0 4’ 1(2—3 ‘ “Kc CFSE. CE" Well SM k CF35; all" was stl Ofcommx 13 HIGH Spud 2585 Ch)” Huou 9.9%) > cFSE CN’ LON gP/d .. QN‘ Qd/kant l& Lew apt d (c) What will be the magnetic properties of [Co(CN)6]3' (paramagnetic or diamagnetic) P _, assuming A0 and Q are the same as in [Co(CN)6]‘? : Co’s—k L otb ’— ——— ’ Loco BPVJ 4):. 4L, Lu: J. EMMAW'RC No WPA‘Q‘Z ELF/’TfiaAk Ccse NW 39o > CFSE was w“) 2&9) 4' 7— 3(a) Him»! (0 K4 4. (20 points) (a) The reaction shown below is responsible for creating "C in the atmosphere. What is the bombarding particle? H §4N+4____)é4C+11H // (ii) gHe or alpha (iii) fl’e or beta (iv) positron (b) Which statement is true about the following reaction? )4N + gHe —~> $70 + {H 13.992 4.0015 16.9986 1.0073 amu amu amu amu «7, @ Energy is absorbed in the reaction (ii) Energy is released in the reaction (iii) No energy change is associated with the reaction (iv) Not enough information is given to determine the energy change (c) Attempts to find the guilty party in the famous gunfight at the OK Corral (Tombstone, Arizone) lead to a detection of a skeleton whose 14C count was about 14.01 cpm/g (the atmosphere activity of “‘C is 15.3 cpm/g). Could it be that we finally vindicated "Doc" Holliday (played by Val Kilmer in the movie)? Explain your answer with the proper calculation. (AALF'LlFi 03: NC is E730 . G A<%>=—Kr=(‘%g%>+ A ((13312) = (L W )+ 5'130 Tears ~r; W28 was Fm walgu‘r Q (K Cw“ mm mm m 1881 7346A.) Tm; Smcsmo Wt: MOT‘ (asap? FROM 71’? A'n‘m‘: a“: Do“ 2"“ — won»! 5. (20 points) A liter ofwater solution contains 0.02 mole per liter Ba(NO,)2 and 0,02 mole per liter Ca(NO3)2, both of which are soluble salts The following solubility product constants are given: | ’ L1 lgfiam 3 "2mg Mg 2 if“: u’ - - l)“ kgftgag);-3r9xm “ Kip; Drum-3’- (3) Determine which of the two salts will precipitate first when adding NaF to the solution. I A” _ __ Lay/0"f IL (gap; “AWL P/ZfiC'pliA tr. NH‘N (F1 *’ =- OUB f4 0.02. M I/ h a - - 39x16” 2 —§ Cafi, W‘” Pmc'P'm“ WW") [F1 v< 001M) 3 q'qX'Q H OMFL was far éqsr, (b) Calculate the solubility ofBaF2 in pure water. 1(3) 2. 2. KS?‘ [EQZQEFQ = S “Fag: ‘3" Idxh-ICJ‘V b: V} ’ Ll : 0.033 M 6. (20 points) (@ Themymmfidddmgmmofi (Cbnflommnka Xl'ji 2; O 03 (N ’H Co 6» oo *" X3 x2 fie Please draw the corresponding diagram for Fe(CN')§3 where one ligand is removed from the z axis (i.e., draw the crystal field diagram). “1 l 3: (b) Which one of the following explanations can exhibit geometrical isomerism? (i) Zn(NH3)2Cl2 (tetrahedral) it! 3 (ii) [CUCI’VTWLL]2+ (square planar) t\ ; 5 (iii) Pt(NH3):Cl2 (square planar) ( (iv) [CoCl‘J'IwIQSCl]2+ (octahedral) ; j 3 (0) Name the following two complex: [Coongxcucg ;\Mviguvaitdeistfv*&l 'H MNHJLCIZ 7. (20 points) Please circle the correct answer. (i) 'J (ii) an (iv) Choose the CORRECT statement. W ‘34; 3) Exothermic r ons are always spontaneous. A, K b) Free e 15 independent of temperature. AC -’ 0‘4 ‘ ‘ A A c A reaction which exhibits a negative value of AS cannot be spontaneous. d) /,l At constant P and T, a decrease in free energy insures an increase in the / entropy of the system. 6:) None of the above statements is true. Consider the freezing of liquid water at -10°C. For this process what are the signs of AH, AS, and AG? 0 ..=p Li 0 . <+ A.“ l L s AH AS AG (9) ( 3 flit-3 4.. (L, a) + ‘ 0 Aug 4 ¢ b) "‘ + 0 If e) - + - A». C: Q W i“ : :, When a stable diatomic molecule is formed from its atoms, what are the sign of AH°, AS°, and AG"? AJ‘AJ’AL AH" AS“ AG" AM 4:) a) + + + t: C; d) b) + - - , C) ,_ + + [32;(9 4 q") d) - - + {e - - The third law of thermodynamics states: a) The entropy of the universe is increasing. b) The entropy of the universe is constant. (c) 3 The entropy is zero at zero K for a perfect crystal. d) The absolute entropy of a substance decreases with increasing temperature. e) The entropy of the universe equals the sum of the entropy of system and surroundings. 10 '«inam (a) (b) (d) (e) (f) (g) (h) (i) G) (20 points) Circle "True" or "False" for each of the following statements. C12 is a strong reducing agent. A catalyst inCreases the activation barrier of a reaction. According to Bronsted and Lowry an acid is a lone pair donor. A mixture of HCl and KCl forms a good buffer. EDTA bonds metal strongly because of entropic effects. dz: is less stable than d"y in square planar complexes. The first name of Faraday was Walter. Geometrical isomers cannot rotate polarized light. The difference in elevation between Los Angeles and Boulder is a state function. It is always true that an indicator is most effective when the pH of the equivalent point is equal to the pK. of the indicator. 11 True True Tme True ,r/‘\ True ‘ //-‘N‘\ True‘ True Tme True /“\\ False alse '7‘ 13% False False (False) {is} False 9. (20 points) (a) The molecules XH and YH below are weak geld with reg bond. However, XH is a stronge han YH. Please g that the Cm—H bond strength is equal in both cases. 0 H H u \ H H\ ,H /C\ "Cq 53‘ H (E ’ \1 I \H H H H H 9 HX HY CON31DUL ’Ni (Burma S'TQC’AUTY I “Buss: 7r A~o y ’ :6: 'f " l c, \ \ / Ci (1/ IC \ H l H [4 H 2‘ :o‘. H ' . H 2 H / C \ g / \L'. H l H Two (a own-nu. 57ft“ » WM“, ".‘1 TH? Cam m w: z X“ :5 We ‘1’ .t. M& w A <5 12 ard to dissocation of the C(1)-H ive the reason for this, assuming ol— W COM-:JQATE. r H o i "t \ ’H'C’. ’ T ° X I \/ H l“ OWE (LQSopA—di TQMCML /' L/‘I 9. (continued) (b) Write a charge balance equation for a system obtained by mixing 0.1 M NaCl and 0.1 M MgCl2 in water. +3 ‘\ ‘ F ‘ ‘i‘ I W *J alwi lllc'tfi Li/v‘q j » lfi l A 3 CL + lol (c) What equation would you use to evaluate the temperature dependence of the equilibrium constant? (d) Extra credit (1 point): Please draw Ludwig Boltzman‘ 10. (20 points) (a) (b) (C) (d) (f) (g) (h) (i) 6) Circle "True" or "False" for each of the following statements. No mass is created or destroyed in chemical reactions. W A blue transition metal complex is less likely to be paramagnetic than a red complex of the same metal. NH3 is a strong field ligand. Anodic protection can help in preventing corrosion. Fuel cells are concentration cells. Arranging your books decreases the entropy in the book cabinet. The most stable isotopes occur when the number of neutrons and protons are equal. Increasing the temperature cannot change rate constants. ’ Enzymes are used by the cell to slow down fast reactions. Spontaneous reactions are equilibrium processes. 14 True mite True Tme b\ I True ‘ ll True (—7 True True True False False alsé ...
View Full Document

This note was uploaded on 01/06/2011 for the course CHEM 105BLG taught by Professor Parr during the Spring '08 term at USC.

Page1 / 14

105bs10_w_sample_final - ,... scime Feb? Aoogaooq)...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online