How many resonance structures are there for carbon trioxide?

1 Answer
Sep 22, 2014

There are three different isomers of CO₃, so we must consider each isomer separately.

Carbon trioxide (CO₃) is an unstable oxide of carbon. It is quite different from the stable carbonate ion, CO₃²⁻.

The three isomers of carbon trioxide are

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Structure 1 has two unpaired electrons and only one resonance contributor.

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Structure 2 has two unpaired electrons and three resonance contributors.

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Structure 3 has no unpaired electrons and one contributor. All three isomers are unstable, but this one is the most stable of the three.

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