Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

POLARITY OF BONDS AND MOLECULES
Polarity: definition
In chemical bonding, polarity refers to the distribution of electrical
charge across the atoms joined by the bond
...

Polarity of bonds:
Bond Polarity is the measure of the extent to which a bond exhibits
polarity
...

The polarity of bonds is caused due to the interaction of the bonds
between molecules and atoms with different electronegativities
...
The electrons eventually spend more time at the Fluorine atom
...
The reasons which lead to the polarity of
bonds are:
1
...

2
...

Formation of a diapole:
A covalent bond involves the mutual sharing of valence electrons of
the participating atom
...

When atoms share their electrons, it tends to happen that the atom
having higher electronegativity than the other pulls the shared pair of
electrons more towards itself
...

The formation of a dipole results in a charge separation in such a type
of bond, with one atom being slightly more positive and the other being
more negative
...

As dipole formation is a characteristic of bond polarity, the molecules
exhibiting dipoles are more precisely called Polar covalent molecules
...
Conversely, the atom with a less electronegative value
acquires a slightly positive charge (+δ)(+δ)
...

If a molecule has more dipole moments than the other, it is more
polar than other molecules
...
in a polar covalent bond, the two bonded
atoms do not share the electrons equally, unless the bond connects two
atoms of the same element
...

The ability of an atom to attract electrons in the presence of another
atom is a measurable property called electronegativity and will produce a
dipole moment
...
A covalent bond with an unequal sharing of electrons and
the electronegativity difference within the range of 0
...
1−2 is called a
polar covalent bond
...


A bond that is formed by the equal sharing of electrons between the
combining atoms is called a nonpolar covalent bond
...
Hence, identical pairs of atoms form a nonpolar
covalent bond
...
50
...
Let us
consider the example of the oxygen molecule
...
This is because
both atoms have the same electronegativity, and electrons are shared
equally between them
...
As a result, the electrons will definitely move towards the
more electronegative element
...

2) The Spatial Arrangement of Various Bonds in the Atom
The shared pair of electrons also experience pulling force from the other
bonded and non-bonded pair of electrons
...
For e
...
Bond Polarity of O-H bond in a water molecule and
acetic acid molecule is different
...


Polarity of molecules:
“A state or a condition of an atom or a molecule inherent in a
body that exhibits opposite properties or powers in opposite
parts or directions
...
A molecule can basically be either polar
molecule, non-polar molecule or an ionic molecule
...
Thus, they end up creating an electrical
pole
...
Whereas the centre of positive charge will be on the
different side
...

Non- Polar Molecules
A molecule which does not have the charges present at the end due to the
reason that electrons are finely distributed and those which symmetrically
cancel out each other are the non- polar molecules
...
For example, consider
water and oil
...
On the other
hand, oil behaves as a non-polar molecule
...
This is because they cannot ever be mixed up
...

• Polar bonds are formed when one atom in the bond has a much
tougher pull towards electrons than the other atom
...
If
one electronegativity value is greater, that atom will pull the electron
closer and develop a partial negative charge, while the other atom
develops a partial positive charge

---