Slide 1 : Polar Bonds
Slide 2 : We know a
COVALENT bond
comes from sharing the
bonding pair of electrons
Slide 3 : F F
Slide 4 : F F The nucleus of each atom
pulls on the bonding pair.
Slide 5 : F F Both atoms have equal pull,
so the bonding pair is shared equally.
Slide 6 : If two different atoms share a bond,
one will pull more strongly
on the bonding electrons.
Slide 7 : H Cl
Slide 8 : H Cl
Slide 9 : H Cl
Slide 10 : H Cl
Slide 11 : H Cl
Slide 12 : H Cl
Slide 13 : H Cl
Slide 14 : H Cl
Slide 15 : H Cl The bonding electrons carry negative charge.
Slide 16 : H Cl The closer they get to the chlorine atom,
the more negative it gets.
The farther they get from the hydrogen,
the more positive it gets.
Slide 17 : H Cl + _ But the charge is only partial.
Hydrogen has not lost the electrons
as in the formation of an ion.
Slide 18 : H Cl There is an unequal sharing of electrons.
Slide 19 : H Cl The partial charge is denoted by a + or –
and the Greek letter delta, d d – d +
Slide 20 : The partial charge is denoted by a + or –
and the Greek letter delta, d d – d +
Slide 21 : d – d +
Slide 22 : A polar bond is a bond in which the
bonding electron pair is shared unequally.
A polar molecule is a molecule
with regions of partial negative (d –)
and partial positive (d +) charge.
Slide 23 : The degree of sharing (equal to unequal)
is determined by the electronegativity
difference between the two atoms.
Slide 24 :
Slide 25 : Two atoms of equal electronegativity
will share the bond equally
Slide 26 : Two atoms with a small difference in electronegativity will share unequally,
resulting in partial charge.
Slide 27 : Two atoms with a small difference in electronegativity will share unequally,
resulting in partial charge.
Slide 28 : This is a polar bond:
The bonding pair is, on average,
closer to one atom.
Slide 29 :
Slide 30 : Two atoms with a large difference in electronegativity will result in a loss
of an electron,
resulting in a full charge.
Slide 31 :
Slide 32 :
Slide 33 :
Slide 34 : F K
Slide 35 : F K
Slide 36 : F K
Slide 37 : F K positive ion negative ion
Slide 38 : A polar bond in a molecule
may make the entire molecule
polar, with one end slightly
positive and the other end
slightly negative.
Slide 39 : Hydrogen chloride is an example
of a polar molecule. H Cl d – d +
Slide 40 : The SHAPE of the molecule
determines whether its polar
bonds make the molecule polar
Slide 41 : In CF4 the fluorines are symmetrically
arranged around the carbon.
Slide 42 : The fluorines all pull on the valence
electrons in opposite directions,
effectively cancelling out the polarity
of the bonds
Slide 43 : CF4 has four polar bonds
but it is a non-polar molecule:
There is no partial charge
on the molecule.
Slide 44 : The two hydrogens of water are
not symmetrically positioned
around the oxygen.
Slide 45 : The O-H polarities do not cancel,
and the molecule carries a partial charge. d – d + d +
Slide 46 : Water is a liquid instead of a gas
because the partial positives and negatives
attract each other.
Slide 47 : This attraction holds the molecules together,
forming a liquid rather than the
spread out molecules of a gas. d + d –
Slide 48 :
Slide 49 :