Transcript IONIC_CHARACTER2.ppt

IONIC CHARACTER
• The IONIC CHARACTER is the difference of electro
negativity that exists between 2 atoms in a
compound.
• The ionic character is used to classify the
type of bonding and can be thought of as a
measurement of a “tug of war” on the
electrons by the atoms.
INCREASING IONIC CHARACTER
NON POLAR
COVALENT:
IONIC
CHARACTER IS
0 TO ABOUT 0.4
POLAR
COVALENT:
IONIC CHARACTER
IS
0.4 TO ABOUT 1.7
IONIC:
IONIC
CHARACTER IS
1.7 AND ABOVE
• Calculating ionic character:
– Look up the electronegativities of the elements in TABLE S.
– Subtract the electronegativities of only two elements at a
time to get the ionic character.
– The ionic character is never negative.
– If one compound has a high ionic character, it will have a
relatively high degree of ionic behavior as compared to a
compound with lower ionic character.. The parameters of
ionic behavior include:
• High melting and boiling points
• The formation of hard crystal lattices.
• Conductive of electricity in the aqueous states, BUT not
conductive in the solid state.
ASSESSING AN IONIC COMPOUND
Example: For a compound formed when Ca reacts with
F; please elucidate the following;
-The Ionic Character to classify the compound
-The formula (criss cross)
-The Lewis dot structure of the reaction.
The ionic character is
(electro negativity of F) – (electro negativity of Ca) = Ionic character
( 4.0) – ( 1.0) = 3.0, it is VERY ionic.
The Formula is
Ca2+ F1-
Ca2+ F1- Ca1F2 CaF2
Transfer Reaction:
F

Ca
F
[
[
F
]
F
]
2
Ca +