2.B.13

[Jordan Kaplan 2E]

2.B.13 asked to draw out the lewis structure of C14H10 and then how many different resonance structures there are. I know how to draw it but I wasn't sure how to find the amount of resonance structures. I was just wondering if anyone had any tricks to figuring out how many or if I just have to draw them all out every time.

[Krutika_Joshi_3I]

The resonance structures are when you can double bond any atom, in this case any of the oxygen atoms because the formal charge of the entire molecule remains the same regardless. So the number of resonance structures equals the number of number of different lewis diagrams you can do where the overall formal change remains the same.