All Flashcards
What is the effect of resonance on bond length and bond strength?
Resonance leads to bond lengths that are intermediate between single and double bonds, and bond strength that is greater than a single bond but less than a double bond.
What is the effect of a large formal charge on the stability of a Lewis structure?
A large formal charge generally decreases the stability of a Lewis structure.
What happens if you don't draw all resonance structures on the AP exam?
You may lose points, as it indicates an incomplete understanding of resonance.
What is the effect of minimizing formal charges on the stability of a Lewis structure?
Minimizing formal charges generally increases the stability of a Lewis structure.
What happens if you place a negative formal charge on a less electronegative atom?
The Lewis structure becomes less stable.
What are the steps to identify resonance?
- Count valence electrons. 2. Draw the basic structure with single bonds. 3. Adjust for octets by converting single bonds to double bonds where needed. 4. Draw all possible resonance structures.
How do you calculate bond order in resonance structures?
Bond Order = (Total number of bonds) / (Number of bond locations)
What are the steps to determine the most stable Lewis structure using formal charge?
- Draw all possible Lewis structures. 2. Calculate the formal charge for each atom in each structure. 3. Choose the structure with the lowest formal charges, with negative charges on the most electronegative atoms.
How do you draw resonance structures for ?
- Draw N connected to three O atoms with single bonds. 2. Add lone pairs to complete octets. 3. Convert one single bond to a double bond, and draw all three possible arrangements with a double-headed arrow between them.
How do you optimize a Lewis Structure?
Calculate formal charges, and then reduce formal charges on atoms by forming double or triple bonds if possible. The most stable structure usually has the lowest formal charges, with negative charges on the most electronegative atoms.
What is the definition of Resonance?
Resonance is when a single Lewis structure cannot fully represent the bonding in a molecule, and the true structure is a hybrid of multiple resonance structures.
What is bond order?
Bond order is the number of chemical bonds between a pair of atoms. It can be a fraction in molecules exhibiting resonance.
What is the definition of Formal Charge?
Formal charge is the charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms.
What is a resonance hybrid?
A resonance hybrid is the actual electronic structure of a molecule or ion, which is represented by a combination of several resonance structures.
What is the formula for calculating formal charge?
Formal Charge = (Valence Electrons) - (Lone Pair Electrons) - (Number of Bonds)