Unformatted text preview: wis structure for CO2 also satisfies
the octet rule!
Which one is correct? OC O OO C All atoms are surrounded by 8e → octet! Formal
Formal charge: the charge assigned to each atom
in a Lewis structure if all atoms had the same
of an atom = number
number of its
isolated atom – sum of all the
to the atom in
Lewis structure 1) Assign all non-bonding electrons
all nonaround an atom to the atom.
2) Assign half of the bonding electrons
to each atom joined by the bond . Formal
Best Lewis structure :
With the lowest possible formal charges on all atoms,
With negative formal charge on the atom with higher
electronegativity. OC O OO C Write the Lewis structure of CH2O: 0
Electron Affinity Ionization energy EN = k ( IE − EA) 8.101 Lattice Energy (Electrostatic Attraction)
Lattice energy (E): much depends on the charges of
ions, the sizes of ions and their arrangement in solid
Q+ : the charge on the cation Q+ ⋅ Q−
r Q- : the charge on the anion
r : the distance between the ions
Compound Lattice energy (E) lattice energy MgF2
MgO 2957 LiF
853 3938 Q= +2,-1
Q= +2,-2 increases as Q increase
increases as r decreases r(F) < r(Cl) Dipo...
View Full Document
This document was uploaded on 02/26/2014.
- Fall '14