Solutions to Bonding and Molecular Structure Homework Problem Set

  1. Draw Lewis dot configurations for,
    1. H, H1+, H1-, and He
      H H1+ H1- He
      H lewis dot structure Hydrogen cation lewis dot structure Hydrogen anion lewis dot structure Helium lewis dot structure
    2. Be, Mg, Ca, and Sr
      Be Mg Ca Sr
      Beryllium lewis dot structure Magnesium Lewis Dot Structure Calcium Lewis Dot Structure Strontium Lewis Dot Structure
    3. Li, Be, B, C, N, O, F, and Ne
      Li Be B C N O F Ne
      Lithium Lewis Dot Structure Beryllium Lewis Dot Structure Boron Lewis Dot Structure Carbon Lewis Dot Structure Nitrogen Lewis Dot Structure Oxygen Lewis Dot Structure Fluorine Lewis Dot Structure Neon Lewis Dot Structure
    4. F, Cl, Br, and I
      F Cl Br I
      Fluorine Lewis Dot Structure Chlorine Lewis Dot Structure Bromine Lewis Dot Structure Iodine Lewis Dot Structure
    5. F1-, Cl1-, and O2-
      F1- Cl1- O2-
      Fluoride Anion Lewis Dot Structure Chloride Anion Lewis Dot Structure Oxide Anion Lewis Dot Structure
  2. Draw Lewis dot structures, determine the bond length, determine the bond energy, determien the bond polarity, determine the oxidation number for each atom, determine the formal charge for each atom, determine the molecular shape, and determine the bond angles for, (note; your may not be able to answer all of these questions for some compounds.)
Compound Structure Bond Length (pm)* Bond Energy (kJ/mol)** Bond Polarity (electro neg)*** Oxidation # FC Shape Bond Angle
H2 lewis dot
3-D
PDB 		74 436 0 0 0 linear N.R.
CH4 lewis dot
3-D
PDB 		110 414 0.40 C = -4
H = +1		 0
0		 tetrahedral 109
NH3 lewis dot
3-D
PDB 		98 389 0.9 N = -3
H = +1		 0
0		 trigonal pyramid 109
H2O lewis dot
3-D
PDB 		94 464 1.4 O = -2
H = +1		 0
0		 bent 109
HCl lewis dot
3-D
PDB 		127 431 0.9 Cl = -1
H = +1		 0
0		 linear N.R.
HBr lewis dot
3-D
PDB 		142 368 0.7 Br = -1
H = +1		 0
0		 linear N.R.
SiO2 lewis dot
3-D
PDB 		NA**** NA 0.7 Si = +4
O = -2		 0
0		 Linear 180
PCl5 lewis dot
3-D
PDB 		209 331 0.9 P = +5
Cl = -1		 0
0		 Trigonal Bipyramid 120
90
CO2 lewis dot
3-D
PDB 		122 803 1.0 C = +4
O = -2		 0
0		 Linear 180
BeH2 lewis dot
3-D
PDB 		NA NA 0.6 Be = +2
H = -1		 0
0		 Linear 180
BF3 lewis dot
3-D
PDB 		NA NA 2.0 B = +3
F = -1		 0
0		 Trigonal Planar 120
CF2Cl2 lewis dot
3-D
PDB 		C-F 141
C-Cl 176		 439
330		 1.5
0.5		 C = +4
F = -1
Cl = -1		 0
0		 Tetrahedral 109
C2H6 lewis dot
3-D
PDB 		C-C 154
C-H 176		 347
414		 0
0.4		 C = -3
H = +1		 0
0		 each C is Tetrahedral 109
C2H4 lewis dot
3-D
PDB 		C=C 134
C-H 110		 611
414		 1
0.4		 C = -2
H = +1		 0
0		 each C is trigonal planar 120
C2H2 lewis dot
3-D
PDB 		C=C 121
C-H 110		 837
414		 0
0.4		 C = -1
H = +1		 0
0		 each C is Linear 180

References:
* Bond Length from Table 9.4 (page 416) of Kotz, J.; Treichel, P. Chemistry & Chemical Reactivity, 3rd ed.; Saunders: Philadelphia, 1996.

** Bond Energy from Table 9.5 (page 419) of Kotz, J.; Treichel, P. Chemistry & Chemical Reactivity, 3rd ed.; Saunders: Philadelphia, 1996.

*** Bold Polarity from Pauling's Electronegativity values, Figure 9.7 (page 423) of Kotz, J.; Treichel, P. Chemistry & Chemical Reactivity, 3rd ed.; Saunders: Philadelphia, 1996.

****NA Not Available

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