How many pi bonds are in #CO_2#?

1 Answer
Dec 6, 2016

2 #pi# bonds

Let's consider the lewis structure of #CO_2#, and we can consult our molecular orbital manifold between the bonding species if need be.

Explanation:

For #CO_2# we have:
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We know that #sigma# bonds form for single bonds (including dative bonds), and that the #pi# bonds will be all of the bonds which form thereafter.

Counting the bonds within the species, I see two #pi# bond, and two #sigma# bond.

Let's place the electron between the bonding oxygen and central atom carbon in our molecular orbital manifold:
enter image source here

Notice how the electron from both species, distributed into the manifold are colored red - can you count the number of #pi# bond that are present within the manifold? I see one #pi# bond within the manifold - and the manifold is done for exactly half of the symmetrical species. So, noting that the other half of the species will follow the same configuration - we can deduce that there are 2 #pi# bond in the #CO_2# species.