# Lewis Structure of SO2 [duplicate]

This question already has an answer here:

What is the structure of SO2? I have seen two different ways the Lewis Structure is written:

The formal charges of the SO2 with the single bond and a double bond is larger than the SO2 with two double bonds. So I would assume that the one with two double bonds is the correct structure. But chemistry books I have looked at (Zumdahl Edition 5 and 7) says that it is the opposite.

Which is the correct Lewis Structure?

## marked as duplicate by Mithoron, andselisk♦, Todd Minehardt, ron, Nilay GhoshDec 9 '17 at 4:30

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

• There is such thing as a "correct Lewis structure." – Zhe Dec 8 '17 at 18:55

## 1 Answer

The Lewis structure most closely resembling reality consists of two resonance structures: the first one posted in the question and its mirror image. The reason is that the octet rule is observed this way (no hybridization of d-orbitals for main group chemistry necessary or possible) as well as the symmetry of the molecule: the two bonds are identical.

• I had the notion that sulfur had expanded valence electrons. So why wouldn't sulfur be able to use them and make the formal charges get to 0 for all three atoms? Also, how does the molecule have symmetry? The bonds aren't identical, one is a single bond and the other is a double bond. – Hawkeye Dec 8 '17 at 19:39
• The identical bonds are a physically observable reality. Expanded valence electrons are an outdated concept refuted by modern quantum chemistry. – TAR86 Dec 8 '17 at 20:05
• How does sulfur make a molecule such as Sulfur Hexafluoride in modern quantum chemistry, since expanded valence electrons are outdated? – Hawkeye Dec 8 '17 at 21:00
• @Hawkeye check out molecular orbital theory. You can easily hold sulfur hexafluoride together without using "outer $d$ orbitals". – Oscar Lanzi Dec 8 '17 at 23:41