Resonance Structures and Formal Charge Flashcards
What are resonance structures?
Multiple possible Lewis structures for a molecule or ion.
What differs between resonance structures for the same species?
The locations of bonds and lone pairs
What is a resonance hybrid?
A single structure that is the average of its resonance forms. The hybrid depicts the true nature of the species.
What is electron-pair delocalization?
The spread of electron density over several atoms rather than just two.
What additional type of bonding occurs in resonance hybrids?
Partial bonds due to electron delocalization.
What causes fractional bond orders?
Partial bonding.
How do you find bond order?
Number of shared electron pairs divided by the number of bonded atom pairs
What is formal charge?
The charge an atom would have if the bonding electrons were shared equally.
How do you find formal charge?
Valence electrons - (1/2 bonding electrons + non-bonding electrons)
OR
Valence electrons - (bonds + dots)
What is the sum of the formal charges in the atoms of a molecule?
0 because the molecule has 0 charge
What is the sum of the formal charges in the atoms of a polyatomic ion?
The charge of the ion
Which considers electrons to be shared equally – formal charge or oxidation number?
Formal charge. For oxidation number, bonding electrons are transferred completely to the more electronegative atom.
Which considers electronegativity - formal charge or oxidation number?
Oxidation number.
Which is the same for an atom in all resonance forms – formal charge or oxidation number?
Oxidation number is the same because electronegativity is the same.
What is the formula for oxidation number?
Valence electrons - (lone pair electrons + bonding electrons)
