The bond order of $\mathrm{Cl}-\mathrm{O}$ bond in ${\mathrm{ClO}}_3^{-}$ is_______________ (nearest integer value).

              Bond order of Cl-O bond =$\frac{\mathrm{Total} \mathrm{no}. \mathrm{bonds}}{\mathrm{Total} \mathrm{no}. \mathrm{of} \mathrm{\sigma } \mathrm{bonds} \mathrm{or} \mathrm{total} \mathrm{resonating} \mathrm{structure}}=\frac{5}{3}=1.6$        

  The bond order is determined this way. There is always one bond $\mathrm{b}/\mathrm{w} \mathrm{Cl} \& \mathrm{O}$. 

Hence, bond order of this 1.6 and its nearest integer value is 2.