Resonance

Question 1

Rules

Answer 1

Don’t move single bonds
All resonance structures must be valid Lewis structures
Don’t move atoms
Remember charges

Question 2

For cations next to double/triple bonds or lone pairs

Answer 2

Push e-s from double/triple/LP towards cation
Move arrows correctly
Check charges

Question 3

For lone pairs next to double/triple bonds

Answer 3

1) Push LP e-s toward double/triple bond
2) move double/triple bond e-s onto farthest atom as lone pair
3) check charges

Question 4

Double/triples with an electronegative atom

Answer 4

1) Push pi e-s from double/triple onto electronegative as a LP
2) check charge

Question 5

Alternating doubles around a ring

Answer 5

1) push doubles all around the ring so each is between s different atom
2) don’t break octet rule
3) treat fused rings as one big one

Question 6

Drawing multiple resonance structures

Answer 6

1) look for relevant patterns to ID the first one

Look for additional patterns after that… -_-

Question 7

Levels of importance

Answer 7

1) fewer charges=more stable
2) charges best if placed on best atom
3) complete octets more stable
4) octet desire trumps best placed charge desire