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					                                     Chem 451 (Spring, 2007)
                                             Exam 2 (100 pts)
Name: ----------------------------------------------, Student Clid #: ----------------------------, March 25, 2007
        LAST, First
Circle the alphabet segment of your Last Name : A-G                 H-L               M-P             Q-Z

Please answer the following questions:
Part I: Multiple Choices (30 pts: 6 @ 5 pts). Please circle the ONE best answer:

    1. What are the types of isomerism may arise in each of the following cases?
         [Zn(NH3 )4 ][Cu(Cl4 ], [Cr(OH)3 (NH3 )3 ]- & [Fe(CN)5 (SCN)]4-
         a) Coordination, linkage and geometrical, respectively.
         b) Polymerization, geometrical and linkage, respectively.
         c) Coordination, geometrical and linkage, respectively.
         d) Polymerization, geometrical and ionization, respectively.

    2. Predict how many unpaired electrons are in [CoCl4 ]2- (tetrahedral)?

         a) 1                    b) 2                        c) 0                     d) 3

    3. Which of the following species is expected to be diamagnetic?
         a) [Fe(CN)6 ]4-                                            b) [Co(H2 O)6 ]2+
         c) [Ni(NH3 )6 ]2+                                          d) [NiBr4 ]2-

    4. Which one of the following has the largest CFSE (absolute value)?
         a) [CoF6 ]3-                                               b) [Co(en)3 ]3-
         c) [Cr(NH3 )6 ]3+                                          d) [VCl4 ]-

    5. Arrange the following complex ions in order of decreasing ∆oct (largest ∆oct = 1 & smalles ∆oct =
       4): [CoF6 ]3-, [CoF6 ]4-, [Rh(H2 O)6 ]3+ and [Rh(CN)6 ]3-

         a) [Rh(H2 O)6 ]3+ > [Rh(CN)6 ]3- > [CoF6 ]3- > [CoF6 ]4-
         b) [CoF6 ]4- > [CoF6 ]3- > [Rh(H2 O)6 ]3+ > [Rh(CN)6 ]3-
         c) [Rh(CN)6 ]3- > [Rh(H2 O)6 ]3+ > [CoF6 ]3- > [CoF6 ]4-
         d) [Rh(CN)6 ]3- > [CoF6 ]3- > [Rh(H2 O)6 ]3+ > [CoF6 ]4-

    6.   Which of the following complexes would show Jahn Teller Effect?
         a) [Cr(H2 O)6 ]3+                                          b) [Fe(ox)3 ]4- (low spin)
         c) [Cu(CH3 CN)4 ]+                                         d) [Cu(NH3 )6 ]2+

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Part II. (28 pts) Nomenclature and Isome rization
1. (16 pts: 4 @ 4 pts) Write the name, formula and/or draw the structure of the following:
   a) [Co(OH)(H2 O)4 (NH3 )]2+



   b) [Pt(H2 O)4 ][PtCl6 ]



   c) Tri-μ-carbonylbis[tricarbonyliron(0)]




   d) tris(ethylenediamine)iron(III)hexacyanoferrate(II)




2. (12 pts) The compound Co(en)2 (NO 2 )2 Cl have been prepared in a number of isomeric forms:
   Isomer A undergoes no reaction with either AgNO 3 or en and is optically inactive. Isomer B reacts
   with AgNO 3 to form a white precipitate, does not react with en, and is optically inactive. The third
   isomer C is optically active and reacts with both AgNO 3 and en. Assuming a coordination number
   6 for the cobalt ion, identify each of the three isomeric forms by name, and Sketch each of the
   structures (please label them as A, B or C).




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Part III. (42 pts) Bonding:

1. (12 pts) A complex of nickel(II), [NiCl2 (PPh3 )2 ] is paramagnetic with a magnetic moment value μ =
   2.96 BM. The analogous complex of palladium(II) is diamagnetic (μ = 0). Include diagrams showing
   the molecular geometry and split of the d-orbitals (CFT) for each complex ion as part of your
   answer.




2. (6 pts) Cyano complexes of transition metal ions (such as Fe2+ and Cu2+) are often yellow, whereas
    aqua complexes are often green or blue. Explain the basis for this difference in color.




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3. (12 pts: 2 @ pts each) Sketch the partial qualitative molecular orbital diagram for metal- ligand π-
   bonding in octahedral complexes with:
  (a) π-donor ligands (Cl- & Br- ligands)        and       (b) π-acceptor ligands (CN - & CO ligands)




4. (12 pts: 2 @ 6 pts) In each of the following complexes, predict the type of hybridization of the
   central atom, rationalize the observed value of the magnetic moment (stated after formula), and
   then identify the complexes as high-spin or low-spin:
    a) [Fe(en)2 (NCS)2 ] (μeff = 5.2 BM)                             b)[Mn(CN)6 ]4- (μeff = 1.8 BM)




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                                    CHEM 451- Spring-2007
                                         EXAM 2

You will have 55 minutes to complete this exam.
The exam has 4 pages plus Periodic Table
When you are told to do so, tear off the Periodic Table cover sheet and use as required during
exam.

Ligand abbreviations:

en = ethylenediamine: H2 N-CH2-CH2-NH2
ox = oxalate ion: C 2 O42-
acac = acetylactonate ion: O=C(CH3 )-CH=C(CH3 )-CO-


     1                                                                                                           2
1    H             Periodic Table of the Elements                                                                He
     1.01                                                                                                        4.00
     3      4                                                                      5     6     7     8     9     10
2    Li Be                                                                         B     C     N     O     F     Ne
     6.94   9.01                                                                   10.81 12.01 14.01 16.00 19.00 20.18
     11     12                                                                     13    14    15    16    17    18
3    Na Mg                                                                         Al Si       P     S     Cl Ar
     22.99 24.30                                                                   26.98 28.08 30.97 32.06 35.45 39.95
     19     20     21   22     23    24      25    26    27    28    29    30      31    32    33    34    35    36
4    K      Ca Sc Ti V               Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
     39.1   40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.93 58.69 63.55 65.38 69.72 72.59 74.92 78.96 79.90 83.80
     37     38     39   40     41    42      43    44    45    46    47    48      49    50    51    52    53    54
5    Rb Sr Y            Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I                                                 Xe
     85.47 87.62 88.91 91.22 92.91 95.94 (98)      101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.1
     55     56     57   72     73    74      75    76    77    78    79    80      81    82    83    84    85    86
6    Cs Ba La Hf Ta W Re Os Ir                                 Pt Au Hg Tl Pb Bi Po At Rn
     132.9 137.3 138.9 178.5 181.0 183.8 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 (209) (210) (222)
     87     88     89   104 105 106 107 108 109 110 111 112
7    Fr Ra Ac Rf Db Sg Bh Hs Mt Uun Uuu Uub
     (223) 226.0 227.0 (261)   (262) (263)   (262) (265) (266) (269) (272) (277)


                        58     59    60      61    62    63    64    65    66      67    68    69    70    71
                        Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
                        140.1 140.9 144.2 (145) 150.4 152.0 157.2 158.9 162.5 164.9 167.3 168.9 173.0 175.0
                        90     91    92      93    94    95    96    97    98      99    100 101 102 103
                        Th Pa U              Np Pu Am Cm Bk Cf Es Fm Md No Lr
                        232.0 231.0 238.0 237.0 (244) (243) (247) (247) (251) (252) (257) (258) (259) (260)




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