Question

The correct order of $Cl-O$ bond lengths in $ClO^{-},ClO_{2}^{-},ClO_{3}^{-}$ and $ClO_{4}^{-}$ is

• A. $ClO^{-} < ClO_{2}^{-} < ClO_{3}^{-} < ClO_{4}^{-}$
• B. $ClO_{4}^{-} < ClO_{3}^{-} < ClO_{2}^{-} < ClO^{-}$
• C. $ClO_{3}^{-} < ClO_{4}^{-}>ClO_{2}^{-}>ClO^{-}$
• D. $ClO_{4}^{-}=ClO_{3}^{-}=ClO_{2}^{-}=ClO^{-}$

Answer 1

Answer: (B)

The correct order of $Cl-O$ bond lengths in $ClO^{-},ClO_{2}^{-},ClO_{3}^{-}$ and $ClO_{4}^{-}$ is as follows
$ClO_{4}^{-} < ClO_{3}^{-} < ClO_{2}^{-} < ClO^{-}$
Bond length $ \propto \frac{1}{B o n d \text{ order}}$
or Bond length $ \propto \frac{1}{\text{Extent of delocalization}}$