Resonance_Structures_rev

Resonance_Structures_rev - electrons. The individual...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Resonance Structures Posted by M.Mure (Jan28, 2008) Resonance Structures We will frequently encounter species in which there is more than one valid Lewis structures. e.g. CO 3 2- Lewis Structure #electrons available C 4 3O 18 2(-) 2 _____________ 24 Join all atoms with electron pairs C O O O 4 at oms w/ oct et s need for C 2e - 2 O 3 x 6 = 18 20 more We do not have enough -----> multiple bond All are valid Lewis structures. Which is correct?? - None We know from X-ray data that all C-O bonds are the same length. The real carbonate ion (CO 3 2- ) is a "hybrid" and cannot be represented by the usual Lewis notation. The three possible structures we have drawn are resonance structures. They all differ only in the position of electrons and are C O O O C O O O but why not et c C O O O -2/3 -2/3 -2/3
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
interconverted by simply moving electrons. "arrow formalism" - a curved arrow () represents the flow of
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: electrons. The individual structures have no real existence. They are called resonance structures or contributing structures. Rules of Resonance Structures 1) Differ only in the position of electrons. Nuclei do not change positions. 2) Each contributing structure must be a valid Lewis structure. 3) Energy of real structure is lower than that of any of the contributing structures. 4) Major contributors have octets around all atoms and minimum charge separation. 5) Negative charges are best on the most electronegative atom and positive charges on the least electronegative atom. C O H H C O H H major e.g. H C CH O H H C CH O H e.g. best C O O O electrons move from areas of high electron density to areas of lower electron density....
View Full Document

This homework help was uploaded on 04/17/2008 for the course CHEMISTRY 625 taught by Professor Waetzig during the Spring '08 term at Kansas.

Page1 / 2

Resonance_Structures_rev - electrons. The individual...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online