Lewis Structures, Formal Charge, Resonance Contributor, Bond Order Flashcards
Lewis Structure must follow what rule?
octet rule. You’ll count up all of the valence e- in a formula, place the least electronegative atom in the center and fill in the e-
exceptions to octet rule?
H - only need 2 e-
Be -only needs 4 e-
B&Al -sometimes onlyhave 6 e- on Lewis Structure bc they are stable enough that way
single bond is called a?
sigma bond
double bonds contain?
one sigma bond and one pi bond
triple bonds contain?
one sigma bond and 2 pi bonds
formal charge =
(valence e-) - (dots) -(bonds)
What bond is longest?
single bond
What bond is weakest?
single bond
Order of bonds from STRONGEST to WEAKEST
triple, double, single
Order of bonds from LONGEST to SHORTEST?
single, double, triple
The Lewis Structure that contributes more (or is the most stable) is generally the structure with atoms that have what?
A formal charge close to 0
If there are two Lewis structures for one formula, how do you determine which one is the resonance contributor?
By whichever structure has the formal charge closest to zero
Remember when you count dots for formal charges…?
You literally count every dot, not groups of dots
Difference in finding formal charge for an atom opposed to the entire compound?
You only count the dots and bonds directly touching the atom, when you are finding formal charge for entire compound you count ALL dots and bonds
What is bond order?
the average length of each bond when multiple contributors are possible, its an average
