U.S. CitiesCity-Data Forum Index
Go Back   City-Data Forum > General Forums > Science and Technology
 [Register]
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
View detailed profile (Advanced) or search
site with Google Custom Search

Search Forums  (Advanced)
 
Old 11-20-2018, 06:47 PM
 
109 posts, read 38,628 times
Reputation: 65

Advertisements

I am stuck on this exercise problem from the book "Chemistry³":

http://www.image-share.com/upload/3878/273.jpg

How do I know that this is the correct electron arrangement?
It seems to me like I can share the electrons in an almost infinite number of ways, like create a pair between the left NN-bond and then take two electrons from the oxygen atom to the right and then take whatever that's necessary to get as close to the octet rule etc;
why is the arrangement in the solution for this problem the correct answer?
Am I really just supposed to "guess" until I find charges that are as low as possible on all atoms, or is there some cleaner and more reliable way to do this?

("Equation 5.1" is just the definition for Formal Charge)
Reply With Quote Quick reply to this message

 
Old 11-21-2018, 05:19 AM
 
Location: Westwood, MA
3,566 posts, read 4,417,235 times
Reputation: 4557
Once you adopt a structure, the right configuration is more a process than just a mere guess. You want to minimize formal charge.

This is helpful: CHEM 101 - Lewis structures
Reply With Quote Quick reply to this message
 
Old 11-26-2018, 09:29 AM
 
4,984 posts, read 4,713,313 times
Reputation: 9278
Is "dinitrogen oxide" the same thing as nitrous oxide/laughing gas/N2O?
Reply With Quote Quick reply to this message
 
Old Yesterday, 12:01 PM
 
Location: Cincinnati near
2,513 posts, read 3,380,191 times
Reputation: 5621
Formal charge has some limited utility when selecting the relative importance of resonance contributors. I don't think it is very valuable in predicting the relative thermodynamic stability of isomers, which is what this exercise seems to be indicating.

We teach Lewis theory because it is a simple first approximation, easy to learn, and a good way to start looking at the common bonding themes seen in introductory organic chemistry. There are much better bonding models presented to first and second year chemistry students, so trying to stretch the utility of something like formal charge seems unproductive to me.

That being said, this application of Lewis theory correctly predicts that NNO has a more stable structure than NON on the basis of formal charge minimization.
Reply With Quote Quick reply to this message
 
Old Today, 08:27 AM
 
15,864 posts, read 13,313,825 times
Reputation: 19735
Quote:
Originally Posted by Markus86 View Post
I am stuck on this exercise problem from the book "Chemistry³":

http://www.image-share.com/upload/3878/273.jpg

How do I know that this is the correct electron arrangement?
It seems to me like I can share the electrons in an almost infinite number of ways, like create a pair between the left NN-bond and then take two electrons from the oxygen atom to the right and then take whatever that's necessary to get as close to the octet rule etc;
why is the arrangement in the solution for this problem the correct answer?
Am I really just supposed to "guess" until I find charges that are as low as possible on all atoms, or is there some cleaner and more reliable way to do this?

("Equation 5.1" is just the definition for Formal Charge)
Central atom is typically the least electronegative. Oxygen is more electronegative than Nitrogen. Start by putting the least electronegative in the middle. No guessing needed.
Reply With Quote Quick reply to this message
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.

Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.


Reply

Quick Reply
Message:


Over $104,000 in prizes was already given out to active posters on our forum and additional giveaways are planned!

Go Back   City-Data Forum > General Forums > Science and Technology
Similar Threads
Follow City-Data.com founder on our Forum or

All times are GMT -6.

© 2005-2018, Advameg, Inc.

City-Data.com - Archive 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 - Top