Transcript Document

Lewis Structures (octet breaking),
Resonance, bond strength and
Length
• Any common octet breaking atoms?
• How many electrons are present?
• What is the central atom?
• Draw a skeletal structure
• Add electrons: do you have enough
to give all atoms octets?
• Yes? Then minimize formal charges if
needed.
• No? Then add double bonds until
you have enough electrons.
• Is it one that is typically found
to have less?
• Is there any reason you chose
those double bonds rather
than placing it elsewhere?
• No? Then draw
resonance structures to
show all equally likely
structures
• Label each with the formal charge
[HCO2]-
O3
• Any common octet breaking atoms?
• How many electrons are present?
• What is the central atom?
• Draw a skeletal structure
• Add electrons: do you have enough to give all atoms
octets?
• Yes? Then minimize formal charges if needed.
• No? Then add double bonds until you have enough
electrons.
• Is it one that is typically found to have less?
• Is there any reason you chose those double
bonds rather than placing it elsewhere?
• No? Then draw resonance structures to
show all equally likely structures
• Label each with the formal charge
[SO3]2-
Line Structures: CH3CHCHCOOH
• Rules
• The end of a line, or a corner is a carbon
• All hydrogens attached to a carbon are assumed
to be there. Do not draw them.
• Don’t forget the three hydrogens attached to the
carbon at an end of a line are there!
• Heteroatoms: aka atoms other than C and H,
need to be written in.
• All hydrogens attached to heteroatoms must be
drawn in.
Line Structures: NH2CH2CH(OH)CH3
• Rules
• The end of a line, or a corner is a carbon
• All hydrogens attached to a carbon are assumed
to be there. Do not draw them.
• Don’t forget the three hydrogens attached to the
carbon at an end of a line are there!
• Heteroatoms: aka atoms other than C and H,
need to be written in.
• All hydrogens attached to heteroatoms must be
drawn in.
H2N
• BENZENE
• C6H6
• 6-membered ring
• Draw the lewis structure
• Be sure to include any resonance structures
• Draw the line structure
• Be sure to include any resonance structures