Chemical Bonding

1
Chemical Bonding

• Molecular Compounds

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Covalent Bonds

• Types of Covalent Bonds
• 1. Single Covalent Bond two atoms share a pair
  of electrons each atom must put one in
• Ex F2

Unshared pair e- not shared between atoms
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F
F
F
F
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F
F
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and
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What makes this bonding work? Atoms have 8 e- in
their outer level to make them stable
3
Covalent Bonds

• 2. Double Covalent Bond 2 pairs of e- are
  shared b/w atoms
• Ex O2

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O
O
O
O
O
O
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and
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4
Covalent Bonds

• 3. Triple Covalent Bond 3 pairs of e- are
  shared b/w atoms
• Ex N2

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N
N
N
N
N
N
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5
Important differences between covalent and ionic
compounds
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Covalent Lewis Dot Structures

• 1. Draw each atoms Lewis Structure
• 2. Connect single electrons until each atom has 8
  e- (H only 2)
• 3. The central atom is often the first atom
  written is usually the atom w/the least of
  e-. (Exception H cant be the central atom)
• 4. Place the unshared pairs around the atoms so
  ea. is stable (8 around it, except H only 2)

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1. NH3
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H
N
N
H
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H
H
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H
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H
2. CO2
O
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C
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C
O
O
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O
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VSEPR Theory

• Explains the shapes of molecules.
• The VSEPR theory states b/c electrons repel each
  other, molecules adjust their shapes so that the
  valence e- pairs are as far apart from each other
  as possible.
• These are called electrostatic balanced positions

9
Shape Formula Bond Angle Electrons
Linear AX2 180o 4 shared 0 unshared
Linear AX 180o 1 shared 3 unshared
Bent AX2 105o 2 shared 2 unshared
Trigonal Pyramidal AX3 107o 3 shared 1 unshared
Tetrahedral AX4 109.5o 4 shared 0 unshared
Trigonal Planar AX3 120o 4 shared 0 unshared Contains a double bond