### Determining Resonance Structures

Posted:

**Mon Nov 06, 2017 2:54 pm**When solving for resonance structures, is there any way of knowing how many resonance structures a molecule has? Or are we supposed to find as many as possible?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=32&t=23169

Page **1** of **1**

Posted: **Mon Nov 06, 2017 2:54 pm**

When solving for resonance structures, is there any way of knowing how many resonance structures a molecule has? Or are we supposed to find as many as possible?

Posted: **Mon Nov 06, 2017 4:11 pm**

I don't think there's a set way of finding the exact number of resonance structures... it's more like you keep doing them until you run out of combinations and find the most stable one.

Posted: **Sun Nov 12, 2017 5:32 pm**

The number of resonance structures is not necessarily given in any other type of way than writing out all possible structures until you have no other ways of writing it. Even though it can be a pain to write them all out, it allows you to not only find how many resonance structures there are, but additionally find the most stable structure in comparison with each other based on each structure's personal formal charge.

Posted: **Sun Nov 12, 2017 11:04 pm**

Sometimes it is clear to see how many resonance structures there are such as when you have 3 atoms bonded to a central atom and one double bond and 2 single bonds. It is clear that there will be 3 different possibilities for the double bond to be in a different place and therefore there will be 3 resonance structures. Yet, sometimes it is more complex and you may need to draw out each structure to find the answer.