Are these statements about resonance true?

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Discussion Overview

The discussion revolves around the validity of two statements regarding resonance structures in chemistry, specifically focusing on the concepts of net formal charge and the octet rule. Participants explore theoretical implications and examples related to these statements.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant asserts that all contributing resonance structures must have the same net formal charge, reasoning that differing formal charges would not make sense in the context of resonance.
  • The same participant challenges the idea that all atoms in contributing resonance structures must have complete octets, citing examples like sulfuric acid where sulfur exceeds the octet rule.
  • Another participant argues that the octet rule is not a strict rule and is limited in scope, suggesting that it primarily applies to elements like neon.
  • This participant also mentions that sulfur can expand its octet due to the presence of d orbitals, referencing sulfur's hybridization in sulfuric acid.
  • A later reply questions the need for self-judgment regarding the correctness of the initial claims.

Areas of Agreement / Disagreement

Participants express differing views on both statements, with no consensus reached on their validity. The discussion remains unresolved regarding the implications of the octet rule and the nature of resonance structures.

Contextual Notes

Limitations include the potential misunderstanding of the octet rule's applicability and the nuances of resonance structures that may not be fully addressed in the discussion.

Qube
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Homework Statement



Are the following statements true?

1) All contributing resonance structures must have the same net formal charge.
2) All atoms in contributing resonance structures must have complete octets.

The Attempt at a Solution



The first one strikes me as true. Net formal charge is just the overall charge on the molecule. It would not make sense if a resonance structure for a molecule differed in formal charge. Plus resonance structures are made by pushing electrons around, not by taking electrons away.

The second one does not strike me as true; there are many violations of the octet rule as we skip past period 2 on the periodic table. Take sulfuric acid as an example; it forms four bonds, giving the central atom a formal charge of +2. That is a violation of the octet rule; sulfur is in the same column as oxygen and only needs to form two bonds to complete its octet. however it forms four.
 
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Octet rule is something like teaching children about whole numbers. Then later on, you teach them about integers. Octet rule isn't a rule; its scope is limited to Neon.

Your argument on the first one is nothing to argue on.

For the second argument, since Sulphur HAVE d orbitals, it can expand its octet and accommodate additional electrons in those orbitals. It is evident as Sulphur in Sulphuric Acid exhibits sp3d2 hybridization.
 
So I'm right about both?
 
You are to judge yourself. :wink:
 
I'll take that as a yes
 

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