What Determines the Bonding Structure of Sulfur Trioxide?

[semc]

Hi peeps can someone help me with this? The central atom would be sulfur correct? So that means sulfur will invoke hybridization sp² would be use since there are 3 bonds? However when we invoke hybridization there are 2 2s electron and 2 2p electrons in the orbital(doesn't really know how to say this but basically i am trying to say they are in the same box). So when you invoke hybridization there will be 4 paired up electron and 2 unpaired electron? From what i know paired up electrons are lone pairs and its the unpaired electron that is used in bonding forming? Does that mean we can't use MO theory to explain this?

I tried searching the lewis dot structure of this molecule and found out that the sulfur forms 1 double bond and 2 single bond with the oxygen atoms. Why is that so? With 2 single bond and a double bond the sulfur would have a formal charge of +2 and oxygen +1. Ain't the molecule more stable if sulfur forms 3 double bond with oxygen since they won't have any formal charge?

 

[chemisttree]

I tried searching the lewis dot structure of this molecule and found out that the sulfur forms 1 double bond and 2 single bond with the oxygen atoms. Why is that so? With 2 single bond and a double bond the sulfur would have a formal charge of +2 and oxygen +1. Ain't the molecule more stable if sulfur forms 3 double bond with oxygen since they won't have any formal charge?

Are you certain that all of the atoms have a positive formal charge?

 

[semc]

I meant -1 for the single bonded oxygen. A typo but still doesn't answer the question

 

[chemisttree]

That's not right.

 

[semc]

Why is that so

 

[chemisttree]

Because the oxygen in SO3 is not a peroxide. Always assume that oxygen is -2 in compounds unless it is a compound with fluorine or if it is a peroxide. If it is a peroxide (oxidation number is -1), you need to rationalize an O-O bond. Can you do that in SO3?

 

[semc]

No idea what you are talking about. Since oxygen has 7 electrons on it shouldn't the formal charge be -1? So can you explain the bonding in the molecule using MO theory?

 

[Borek]

oxygen has 7 electrons on it shouldn't the formal charge be -1?

Where is the 7 coming from? 6 for a free atom (as if it existed, but that's what we see in periodic table) or 8 in compounds (when it gets noble gas configuration).

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[semc]

I meant when i drew the lewis dot for sulfur trioxide the central sulfur forms 2 dative bond with 2 oxygen and a double bond with the other one so i am talking about the one with the single bond. Why can't the sulfur form 3 double bond with all 3 oxygen atom?