Question

Which of the following facts given is not correct
I) Bond order: $H_2^{-}=H_2^{+}>H_2$
II) $O_2^{+},NO,N_2^{-}$ have same bond order of $2\frac{1}{2}$
III) Bond order can assume any value including zero
IV) $N{O}_3^{-}$ and $B{O}_3^{-}$ have same bond order for X-O bond (where X is central atom)

• A. I, II and III
• B. I and IV
• C. II and IV
• D. I and II

Answer 1

Answer: (B)

I and IV

$\text{Bond order}=\frac{1}{2}\text{[Number of bonding electrons - Number of anti bonding electrons]}$

$I)\text{Bond order of}{H}_2^{-}=\frac{1}{2}[2-1]=0.5$

$\text{Bond order of}{H}_2^{+}=\frac{1}{2}[1-0]=0.5$

$\text{Bond order of}{H}_2=\frac{1}{2}[2-0]=1$

Bond order of $H_2$ is greater than $H_2^{-}$ and $H_2^{+}$.

$II)\text{Bond order of}{O}_2^{+}=\frac{1}{2}[10-5]=2.5$

$\text{Bond order of}NO=\frac{1}{2}[10-5]=2.5$

$\text{Bond order of}{N}_2^{-}=\frac{1}{2}[10-5]=2.5$

$III)$ Bond order can have any value. And a bond order equal to zero implies that there is no bond at all between the atoms.

$IV)$ $N{O}_3^{-}$ and $B{O}_3^{-}$ do not have same bond order.