Question

Among the given species the one which contains weakest carbon- oxygen bond : ${\text{CO}}_{\text{2}}\text{,}{\text{CH}}_{\text{3}}{\text{COO}}^{-}\text{,}\text{CO,}{\text{CO}}_{\text{3}}^{\text{2}-}$

• A. $C{O}_2$
• B. $C{H}_{3}CO{O}^{-}$
• C. $CO$
• D. $C{O}_3^{2-}$

Answer 1

Answer: (D)

$\text{Bond}\text{strength}\propto \text{Bond}\text{order}$

Bond order is determined through resonating structure. Among the given species, the bond dissociation energy of $C-O$ bond is minimum in case of $C{O}_3^{2-}$ by which $C-O$ bond become more weaker in $C{O}_3^{2-}$ or the bond order of $C{O}_3^{2-}$ (1.33) is minimum so the bond become weaker.