This was a question on a review sheet for Lewis structures.

Now I could draw $\ce{SO4^2-}$ with no issues, but I can't make sense out of $\ce{SO4^2+}$ because I can't even make bonds to all $\ce{O}$ without exceeding the number of bonding electrons.

This is on a high school AP review so it is possible that there are exceptions to the normal rules, but I can't see how any of them apply. I could just chop electrons off the oxygens and leave it depleted, but I don't imagine that is a stable form of a cation which would exist?

A quick check doesn't turn up anything so is this a real thing or was it just a typo?

  • 11
    $\begingroup$ Looks like a typo. $\endgroup$
    – aventurin
    Jan 2, 2017 at 23:06

1 Answer 1


How about $\ce{O=O+-S+=O+-O-}$ ? I don't know if it exists but it is a closed shell species and has a delocalized pi bonded structure that might give it some stability.

  • 1
    $\begingroup$ A better resonance structure of your suggestion would be $\ce{O=\overset{+}{O}-S-\overset{+}{O}=O}$ which has less formal charges, is more symmetric and is still conjugated. $\endgroup$
    – Jan
    Jan 3, 2017 at 22:33

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