presentation on chemical bonding topics- .Types of bonds .Octet rule .Valence bond theory .VSEPR theory thank you!!

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2. b
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5. -
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Na
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6. The
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Rule – Ionic Compounds
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7. -
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Na:
22s22p63s1
1s
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Na
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Cl: 1s22s22p63s23p5
--
Cl
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 Sodium has 1 valence electron - -  Chlorine has- 7 valence electrons
 An electron transferred gives
each an octet
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8. This transfer forms ions, each with an
octet forms Na+ 1s22s22p6
Cl- 1s22s22p63s23p6
The resulting ions come together due to
electrostatic attraction forming Nacl
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9. Properties of Ionic Compounds
Structure:
Melting point:
Boiling Point:
Electrical
Conductivity:
Solubility in
water:
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Crystalline solids
Generally high
Generally high
Excellent conductors,
molten and aqueous
Generally soluble
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10. Covalent Bonding
The bond arises from the mutual attraction of 2 nuclei
for the same electrons.
HA + HB
HA
HB
A covalent bond is a balance
of attractive and repulsive forces.
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11. A covalent bond is formed by the overlap of orbital's of
one atom ,with the orbital of another atom
Conditions for overlapping are :
1. Only an orbital with unpaired electrons is eligible for
overlapping
2. For orbital to overlap, the electrons in overlapping
orbital's should spin in the opposite direction
3. After overlapping the shape of orbital's change such
that a greater electron density Appear between the
nuclei of atoms along internuclear axis
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12. The factor which decides the strength of covalent
bond is the extent of overlap, it depends on the
shape of orbital's .The spherical ‘s’orbital’s can
not overlap efficiently, where as the extent of
overlapping the dumb bell shaped
p orbital's more
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13. Overlapping Of Orbital's
s-s overlap
It involves mutual overlap of half filled s-orbitals of the atoms
approaching to form a bond.
s-p overlap
It involves mutual overlap of half filled s-orbitals of the one
atom with half filled p-orbital of the other..
p-p overlap
It involves mutual overlap of half filled p-orbitals of the two
atoms.
Order of strength of overlapping :
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p-p > s-p > s-s
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14. Sigma bond (σ)
Sigma bond is formed by an axial or head-on overlapping of pure atomic orbital's
It is end to end overlap. Sigma bonds are re presented by Greek latter σ
Examples: (σ bond)
Pi bond (∏)
A pi body is formed by the sidewise overlapping of pure atomic orbital's.th
extent of overlapping is less, hence a pi bond is weaker than σ bond
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15. A bond pair means 2 electrons involved in bonding
Alone pair means a pair of 2 electrons not involved in
••
bonding
•
H
Cl •
••
Unshared or
lone pair (LP)
shared or bond pair
This is a LEWIS ELECTRON DOT structure.
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16. VSEPR theory and Molecular Geometry
(Valence Shell Electron Pair Repulsion)
This theory helps in explaining the shapes of single covalent
molecules. according to this theory the Various electron
pairs around a central atom orient themselves in a such way
that there is minimum repulsion and maximumstability
The decreasing order of repulsions among electron pairs is
as under
Lone pair -Lone pair > Lone pair-Bond pair > Bond pair -Bond pair
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18. Steric Number 1
1 atom bonded to another atom
Steric
No.
Basic
Geometry
0 lone pair
1
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1 lone pair
2 lone pairs
3 lone pairs
4 lone pairs
linear
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19. Steric Number 2
2 atoms, or lone electron pairs, or a combination of
the two, bonded to a central atom.
Steric
No.
2
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Basic Geometry
0 lone pair
linear
1 lone pair
2 lone pairs
3 lone pairs
linear
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20. Steric Number 3
3 atoms, or lone electron pairs, or a combination of
the two, bonded to a central atom.
Steric
No.
Basic Geometry
0 lone pair
1 lone pair
2 lone pairs
bent / angular
3 lone pairs
linear
3
trigonal planar
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21. Steric Number 4
4 atoms, or lone electron pairs, or a combination of
the two, bonded to a central atom.
Steric
No.
Basic Geometry
0 lone pair
1 lone pair
2 lone pairs
3 lone pairs
bent / angular
linear
4
tetrahedral
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trigonal
pyramid
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22. Steric Number 5
5 atoms, or lone electron pairs, or a combination of
the two, bonded to a central atom.
Steric
No.
Basic
Geometry
0 lone pair
1 lone pair
2 lone pairs
3 lone pairs
trigonal
bipyramid
sawhorse /
seesaw
t-shape
linear
5
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23. Steric Number 6
6 atoms, or lone electron pairs, or a combination of
the two, bonded to a central atom.
Steric
No.
Basic
Geometry
0 lone pair
1 lone pair
2 lone pairs
Octahedral
square pyramid
3 lone pairs
square planar
6
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24. Steric Number 7
7 atoms, or lone electron pairs, or a combination of
the two, bonded to a central atom.
Steric
No.
Basic
Geometry
0 lone pair
1 lone pair
pentagonal
bipyramidal
2 lone pairs
3 lone pairs
pentagonal
pyramidal
7
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