Question

The correct order of increasing $C-O$ bond length in $CO$, $C{O}_3^{-2}$ and $C{O}_2$ is:

• A. $C{O}_3^{-2}<C{O}_2<CO$
• B. $C{O}_2$ < $C{O}_3^{-2}$ < $CO$
• C. $CO<C{O}_3^{-2}<C{O}_2$
• D. $CO<C{O}_2<C{O}_3^{-2}$

Answer 1

The correct option is D $CO<C{O}_2<C{O}_3^{-2}$

The bond order of $CO$ is $3$.

The bond order of $C{O}_2$ is $2$.

The bond order of $C{O}_3^{2-}$ is $1.33$ (due to resonance).

Since, $bondlength\alpha \frac{1}{bondorder}$

So, bond length order is $CO<C{O}_2<C{O}_3^{2-}$.