C nem 7 0 ft ottAV few to 0 Chemistry 20A Midterm II Fall 2010 November 19 2010 Vt1 Problems 3 0 1 50 pts 2 50 pts 3 50 pts 4 50 pts Total pts h 6 626 x10 34 Js kB 1 38 x 10 23 J ICI e 1 6 x 10 19C me 9 1 x l0 kg mp 1836 R 0 0821 L atm mol l ICI c 2 998 x 10 8 mil 60 8 854 x 10 42 C 2 TI The Periodic Table of the Elements 1 2 El He r 3 4 Li 4 Be 6 941 5 B 1662 10 4 1 ISA 9 112182 II 12 Na 1 Mg 19 20 21 22 23 24 25 26 27 28 29 K Ca rs Sc Ti V Cr 0 Mn Fe Co Ni Cu t 27 944774 14 149171 44708 44 957910 47 147 37 38 39 40 Rb Sr 94 6 49 1670 07 63 55 56 Cs r Y Zr 30 31 Zu Ga 34 35 36 Ge As Se 71494 Br 79 961 Kr 52 53 54 1 Xe 61504 6616 69 727 726 74 92190 46 47 45 49 50 51 Nb Mo Ru Rh Pd Ag Cd In Su 74 Ta t W 13 177 La Hf 132 904 Ba 87 88 89 104 Fr Ra RI 33 566104 9644 4741 32 45 73 Ac 34 0124 32 9732 09 72 1221 1 18 Ar 44 57 7 7 22264 Ii CI 59 441 1111 1411145 6 S 43 4 6 76 iniin 107 10570 113547 109 26r7 75 76 77 78 79 Re 4 Os 1r Pt Au 10 Ne P su6I4 Tc 9 F 15 42 749 669 a 0 674 19649 06969 23 9094 27 074072 26 1747 96971791 7 1 0491 7 9 99 IS 122 14 Si 7 N 7 17479 14 120474 41 4e 4466 44 91 224 7777 6 13 Al 211 961 972 24 34170 6 C c61 6 11 0107 Sb I 996 Te 1177911 6644 114 0 6 74 114710 9997746 1 71 7611 rm 1 9 7 60 80 81 82 83 4 Hg Pb 144 2012 114 BI Po mono Quo 1 set 91 1447 85 7 19 462 2 491 2 4 56 1710 5474 6704 199 24 192 111 202076 05 106 107 108 109 l9 076190 74675 110 I11 T1 Th 149 11 112 113 Sg Bh i Hs 12671 12161 3691 272 an 61 62 63 64 65 66 67 68 69 70 71 Eu Gd Tb Dy Ho Er Tm Yb Lu IM 22651 6 207 12674 58 59 60 Ce Pr Nd 40 116 90 91 Th Pa 212 OUP 24 92 U 2 114937M p0 11749 Pm Sm p 41471 15940 93 94 672944 95 Np Pu Am 077 0964 46 177 7 4 49 n 151 92724 6 64 47 I61 10 94622 64 93012 96 97 98 99 Cm 4414696 12443047112419 Bk 1417 Cf flu 03311 Es 44464 64 772 I 66 6 169 76 100 Fm 66 76 2 77 Rn At A 12 1 iia 77 i 6 4 144 41121 101 949722 171 04 776742 1147077 102 103 Md No Lr M 249 67 476 974 1 50 pts a 10 pls What is Koopmans approximation b 20 pts Explain the reasoning behind the Born Oppenheimer Approximation C 20 pts Why can two arbitrary diatomic molecules with the same bond order have different bond energies Give an example and explain how this could be possible tA ot tire cL7a t o fh t s 5 y r v t 1 st eitiMA 4 1 40 1 cad tsr I 47 C btl t ryc E 1 41 t Ar er CtivI tek in 4 UL 1J dp 2 4 4 A 0 661 a 1 vtut i 0 1 9A t kt 14 iod r e t 7 4 stv 7 r 1 4 4 4 itt T1A A ts 7 1 of t e f e ef t cc vfi i r c CA r 4p re w 1 0 tl It S cr evi 11 vr r1ce 4e Jiff k idi A 4 cj kti ft 4 r rqf f f A d i ct e1 114 1 t 4 4 I L411 4 444 ThT P a 2 50 pts a 30 pts Calculate and plot the photoelectron spectrum PBS of He for a 75 eV photon as a function of the electron kinetic energy and the orbital ionization energy Assume photoelectron peak intensities are the same heights in your plots b 1 0 pts Why is there no vibration information in the He PBS c 10 pts What is the primary reason for the different ionization energies for the two He electrons ri 2 IC 1 4 5 IA vt frth 4 h LET PR 16 10 ku 1 t P 12a5 r fit V I toJ 0 1 1 4 5 L e C v ci e r 41 4 re el Is 2 s t 2 p f y1 4 41 4u j 5 2 2 2 p a 20 pts Construct the MO correlation diagram for CO and CO I and give the 3 50 pls 111 a r molecular electron configuration for both molecules b 15 pts Sketch the electronic potential energy curves both for molecules on the same graph show the relative bond energies equilibrium lengths and first 3 vibrational energy levels c 15 pts What are the HOMO and LUMO in these two molecules Make a sketch of these two orbitals Are the molecules diamagnetic or paramagnetic b ifkif s I zub 7 Yr 1 Z T 1 1 1 fr 171 72 2 177tyr ii itkiU Pri I IL 6 C C t m19 ein x 5 TrAr g r fi LO 172 7 yi 6 tin A 9 a1 3 A l 72 0 c t ict n n entL4C tr 14 r e1v1 4 ei ity 4 50 pts a 15 pts What is a possible Lewis dot structure for C2F4 b 20 pts What is the geometry of the molecule include estimated bond angles in your structure and please explain how your molecular structure was derived c 15 pts Sketch the pi bonding pi anti bonding and non bonding orbitals for this molecule in order of increasing energy and explain your reasoning C I I f ble el tr k IA 3 Le frivoucl 4 p1 etc 7 3 fro 0 0 K4 el P e Lo 1 4 11 1 L 4 44 1 L5 Ft I JJ E e I Lit e s vv kJ 0 Ce 5kA JJJ Lart kJ otv e t xe 44 A 1 kc I fryi h C ti n me