Quiz Grade _________         Quiz 7       Recitation Section ____
March 15, 1996                   CHM 1045 -- 8:00 am -- Dr. Light
     Names           SSN                Names          SSN

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(2)   1.For each of the following ions, draw one Lewis Dot structure
     in which the central atom (underlined) has an octet of
     electrons.  Indicate the formal charge by each atom in the
     structure.

     SO3-2                    BrO2-1














(4)   2.For each of the above two Lewis structures, draw two resonance
     structures in which the central atom has a zero formal charge.
     Indicate the formal charge by each atom in the structure.











Average Bond Energies (kJ/mol)

Single Bonds:

C-H   413      N-H  391       O-H  463       F-F   155
C-C   348      N-N  163       O-O  146       
C-N   293      N-O  201       O-F  190       Cl-F  253
C-O   358      N-F  272       O-Cl 203       Cl-Cl 242
C-F   485      N-Cl 200       O-I  234  
C-Cl  328      N-Br 243                      Br-F  237
C-Br  276                     S-H  339       Br-Cl 218
C-I   240      H-H  436       S-F  327       Br-Br 193
C-S   259      H-F  567       S-Cl 253       
               H-Cl 431       S-Br 218       I-Cl  208
Si-H  323      H-Br 366       S-S  266       I-Br  175
Si-Si 226      H-I  299                      I-I   151
Si-C  301
Si-O  368


Multiple Bonds:

C=C   614      N=N  418       O2   495
CðC   839      NðN  941
C=N   615                     S=O  523
CðN   891                     S=S  418
C=O   799
CðO  1072


(4)   3.Calculate þH for the following reaction using the bond
     energies from the table above.

     C2H4      +    3 O2   ----->   2 CO2     +     2 H2O