105bs10_w_sample3

105bs10_w_sample3 - .H 2 Chemistry lOSbL First Letter or...

Info iconThis preview shows pages 1–10. 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
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: .H 2 Chemistry lOSbL First Letter or PLEASE PRINT YOUR NAME IN BLOCK LETTERS Fall 1995 Last Name Exam #3 Name: October 3 l, 1995 Professor Arieh Warshel Soc. Sec. #: T.A.'s Name: Lab Day and Time: POINTS _— —— - -— -_ "—— Please Sign Below: I certify that I have observed all the rules of Academic Integrity while taking this examination. 5 TOTAL INSTRUCTIONS: 1. There are 5 problems on 10 pages in this exam. Please check to see that you have a complete exam. 2. Please show all of your work. Useful Physical Constants and Equations: Avogadro's number N = 6.022 x 1023 mol'l Universal gas constant R = 0.08206 L atm K" mol‘1 = 8.314 I K“ mol'l Faraday's constant F = 96,485 C mol‘1 KP : [9(an lnk= + lnA if ax2+bx+c:, then x=jiifi PV=nRT -W=q§ AS=kan AG=-nF§ AG=AG°+ RT an AG=AH -TAS E=q+w AG°= -RT 1n Keq E=hv=mc2 Mugs ——T— T+AS VIA V118 AH° 1 06° 1 5° Substance (kd m01 ) (kd mo1‘ ) (J K.1 m01‘1) 51205151 —41 8 134 113 NH.,(g) —46 19 —1664 1925 NH31a0) —80 83 —26 6 110 1114:4351 —132 5 —79 50 112 5 1914,0115) —315 4 —203 9 94 6 WW1 50 42 .. __ NH;-CO-NH2(S) —3332 —1972 1046 (NH.)ZSO.(s) —1179 3 —900 35 220 3 6(9) 3145 2791 1631 9(5. whne) O O O O 44 4 P15. red) —15 —14 29 mg) 54 59 24 4 2799 PC5191 43064 —2553 311 7 PC1557) —395 9 —324 6 353 As191 253 7 2123 1741 As(s, gray metal) 0 O O O 35 A5.<g) 149 105 289 ____.__._____________________________ 0(9) 247 52 230 09 160.95 02191 0.0 00 20503 0,191 142 153 4 235 01-119) 42 09 37 4 183.63 OH‘1aq1 —229 94 —157 30 -105 H2019) —241 53 —225 59 155,72 H2001 —255 54 —237 19 59 940 Hyozm —157 6 —1 13 97 92 52020171 —191 1 —13167 -—' S191 222 5 1523 167 72 S15 rhomblc) O O O O 31 9 S15 m0nocl1n1c) 0 3O 0 096 32 6 52-130) 41 5 53 7 -— 50191 79 55 53 47 221 9 $0219) —295 9 —300 4 245 5 80319) —395 2 —370 4 255 2 H2519) —20 15 —33 02 2055 H2590) —39 —27 4 122 __________________________________,. F191 76 6 59 4 155.64 Mac) -329 1 —276 4 —9 6 F219) 0 o 0 o 203 HF19) —259 —271 173 5 C119) 121 39 105 40 155 09 C1‘(aq) _16746 —13117 552 C1219) 00 0 0 22295 6101.341 — —37 43 1 007191 103 123 249 C10;(aq) -69 0 — 1O 7 101 4 VA 0 0 Substance 1111598 _ A6298 _1 529g _ (KJ mol 1) (KJ mol ) (JR 1 mol 1) CH,COOH1ao1 —488 453 -399 6 - CH,COO‘(aa) —488 871 -372 5 — <COOH),1s1 —826 8 -697 9 120 (COOH1,1aq1 —818 3 -—697 9 — 81:20:18» —818 8 —698 7 154 903—6141 —824 2 —674 9 51 o HCHO1g) —116 —110 2187 HCHo<ao1 .- —130 — CH,OH(g) —201 3 —161 9 236 CH,OH(.’) -238 64 —166,3 127 01,0111”) —245 9 - 1 7512 132 3 C2H50H19) —235 4 - 16816 282 C2H50HU) —277 63 ~174 8 161 614,004,157) - 184 05 -11292 267 1 CHJCHOm) -—166 4 —1337 266 CH,CHO(/) _ 195 _. - CHaCHO1aa1 —208 7 - _ CH,NH,(91 —26 28 241 5 CHJSHM -12,4 0,88 254 8 C,H,Zo,1s) —1260 ~9192 2889 5119) 368 4 3239 167 86 $1151 0 o o o 18 7 S1O(g) —1118 -1371 2061 510,15, quartz) ~859 4 —805.0 41 84 (36(9) 328 2 2908 167 8 691s) 0 0 00 42.42 Sn19) 300 268 168 4 SM; gray) 2 5 4 6 44 3 Mi whnte) 0,0 0.0 51 5 Pblg) 1939 1610 175 27 P1213) o o o o 64 89 F’b’flaq) 1 6 —24 3 2f PbO(s. rod) —219 2 — 189 3 67 8 8601s, yellow) —21 7 9 — 188 5 69 5 Pb021s1 —2766 ‘2190 766 _M N19) 472 646 4551512 153195 N219) 010 0.0 191 49 MW) 252 325 134 N019) 90 374 86 688 21062 N02(9) 33 85 51 840 240.5 Nome) —106 -34 5 125 Noam) -—206.57 - 1 1o 6 146 19,019) 81 55 1036 220 o N20318:) -1o 8 138 28 N20.19) 9 661 98 286 304 3 l. (20 points) Given the following information BaSO4 —+ Ba+2 +50;2 Kw: 1.1 x 10*“ SrS04 —+ Sr+2 + 5032 Ksp = 2.8 x 10-7 Answer the following questions: (i) What is the solubility of pure SrSO‘a in water? lehlL‘gog’j L Lag ,lo‘g ~‘1 )8: 215404.. 1 5.1” W (ii) Which cation (Ba‘2 or Sr”) will precipitate first by adding Na1504 to a solution mixture of 0.2 M Ba+2 and 0.001 M Sr”? Explain. ,, 4-?!) , -m . , if g 61 [EokrlBuz Mlo /0a2 ig'fikHl {—4 {45 ,0 0a} « -7 - ‘ y «1) (SOMJM 2:18 lo 3/0 om) v 73‘”) (iii) How much Sr” will be lefi in solution afier adding 0.001 mole 5032 to 1 liter of the solution of the above problem (ii)? ‘5 .1 i V H) {Cl/.9) \qu )1? M) A H : my A l {int WWW? (set )g s M, So gamfi go,2-o.aol 02w00m ,/ , l l Miami oi {W t1 7 WWW «wow v .1 w, ‘3 (0,240 ow >0» H W igfi‘f‘fifsij< 3 x A g. a l ( A” xwom M, @4541”) I (1)00! ~20 ;:l ' M A); y 5,55%! {.4 (h ‘94': I} DO “ “TL‘UD fix '“'~"""‘f:::r:; ........... —Wm ''' M'" 2. (i) (ii) (20 points) What is the pH of a buffer that is 00800 M in lactic acid, HC3Hjo3 and 01000 M in sodium lactate? For lactic acid K‘ = 1.4 x 10“. \iX a \nQLi O “(K—X) J i X 7- i, 12 l!) , Ml:3m Write mass balance and charge balance equations for the conditions described in the above problem (i). Mi) line}? {L a"): (ti?) 3‘ (20 points) (i) Consider the diagram of a potentiometric titration curve shown below: : consider.- tho diagn- at n pot-numeric amnion m shown balm. 12.0 10.0 gglation 8'0 Equivalence in flask 2'3 Pomt 2.0 7510 15202530354045 mL of 0.115 M NaOH Add“! to flask Which one of the following indicators would be the best one to use for this titration? Indicator pKI methyl red 5.3 W01 blue 6.8 m 8.8 phenolpthalein 9. 1 oi NV (ii) Which process from the following list would have a negative value of ASK- 6W,“ S in!) (a) beach erosion (W SjSM ‘5 “U tum-k) ‘15 (b) breaking a window ( Nu s3: lrwx i; W wmclM) (cl dissolving alcohol in water ( M, s3 s M o 5 ‘MJ SJ w“! w J Gd» making your bed ( Hu 5‘; s M i 5 Nu in J) (iii) Which molecule below should have the highest gas-phase absolute entropy at 25°C? 1“) H2 <33 CzHe (c) Csz (d) CH4 (e)‘ CzHi ‘ (continued) (iv) At equilibrium which of the following conditions are always satisified? (8) AH = o /?-4\ (b) AG° < 0 ( (C)w Ag: 0 / (d) AS = o y/// (v) In endothermic reactions, which occur in Spontaneous ways, which of the following conditions are always satisifed? /.~——.\“‘ / ~\ “<5 AS>0 WW leIsSl (c) AH < 0 o 0 (vi) Which of the following sequence pictures (a or b) is consistent with the second law of @ thermodynamics? 4. (20 points) (i) Calculate the value of AG° (in 1d) for the following reaction at 25°C. (R = 8.314 J/K-mol) N2(g) + 3Hz(g) 2 2NH3(8) ch= 50 x108 4 (ii) What will be the direction of the reaction above in each of the following cases? 2, (a) Q=0 r“: ‘0 C” “l 3 (b) Q=10‘ m 3H Cw ‘4 2 (c) Q =10” 321% o > u (iii) How will the equilibrium constant change with temperature? AGO I; M ’Wy'fla U‘l U’l S. (20 points) Consider the Br2(l) --> Br2(g) vaporization process. For this process AS° = 93.0 J/K mol, AH" = 31.0 kJ/mol (i) What is the boiling temperature of Br2 at 1 atm? 0 AG: 0 1/ AH ~ @3469 N A H l 60 o who-i9 * “19::— 34% :- 33% A 50 ,0 0 (ii) What will be the sign of AG for boiling of Br2 at 100°K and what does it tell us about the direction of the vaporization process? for)! (i , AHQ‘VTASDi 'SlOOO “OOL93 A 2’70 Pin/diva an}; “i0 i3 ibfiwj (iii) What does the positive value of AS° tell us about the relative order of the system? {5! WV Cu 4 l In (1613 mum £550xd’im ‘ I W F.“ (iv) What is the equilibrium constant for the vaporization process at the boiling temperature? .Q «A W 35% Ali” $0,; 38 :0 a} “mil. T ’i.\ : LAC: 0 10 i)” ...
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 / 10

105bs10_w_sample3 - .H 2 Chemistry lOSbL First Letter or...

This preview shows document pages 1 - 10. Sign up to view the full document.

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