Chapter 9, Problem 109AP

Carbon monoxide $\left(\text{CO}\right)$ is a poisonous compound due to its ability to bind strongly to ${\text{Fe}}^{\text{2}}{}^{-}$ in the hemoglobin

molecule. The molecular orbitals of $\left(\text{CO}\right)$ have the same energy order as those of the N₂ molecule, (a) Draw a Lewis structure of $\left(\text{CO}\right)$ and assign formal charges. Explain why $\left(\text{CO}\right)$ has a rather small dipole moment of 0.12 D. (b) Compare the bond order of $\left(\text{CO}\right)$ with that from molecular orbital theory. (c) Which of the atoms $\left(\text{C or O}\right)$ is more likely to form bonds with the ${\text{Fe}}^{\text{2}}{}^{-}$ ion in hemoglobin?