Question

$Cl?O$ bond order in perchlorate ion is

• A. $1.33$
• B. $1.50$
• C. $1.75$
• D. $1.90$

Answer 1

Answer: (C)

$1.75$

Answer 2

Perchlorate ion $(ClO_4)$ exists in fiollowing racemic forms

Thus, $Cl?O$ bond order
$= \frac{\text{Total no. of bonds between two atoms in all resonating forms}}{\text{No. of resonating structures}}$
$= \frac{2\times 3 +1}{4} = \frac{7}{4}$
$= 1.75$