Question

Which of the following have same bond order?

• A. $C{N}^{-}$
• B. ${O_2}^{-}$
• C. $N{O}^{+}$
• D. $C{N}^{+}$

Answer 1

Answer: (A), (C)

$N{O}^{+}$

Now, here if we have to check the bond order of the following molecules, first let's draw the MO energy level diagram:

Now,for :

$C{N}^{-}⟶$ 1 more electron in the energy level diagram

${O_2}^{-}⟶$ 1 more electron in the energy level diagram

$N{O}^{+}⟶$ 1 less electron

$C{N}^{+}⟶$ 1 less electron

Now, Bond order = $\frac{1}{2}$[Bonding electrons (BE) - Anti bonding electrons(ABE)]

For $C{N}^{-}$ Bond order = $\frac{1}{2}$[10 - 4]=3

For $O_2^{-}$ Bond order = $\frac{1}{2}$[10 - 7]=1$\frac{1}{2}$

For $N{O}^{+}$ Bond order = $\frac{1}{2}$[10 - 4]=3

For $C{N}^{+}$ Bond order = $\frac{1}{2}$[8 - 4]=2

Therefore, bond order of $C{N}^{-}$ and $N{O}^{+}$ is same.