Question

Consider the statements
I. Bond length in $N_2{}^{+}$ is $0.02\mathring{A}$ greater than in $N_2$.
II. Bond length in $N{O}^{+}$ is $0.09\mathring{A}$ less than in $NO$.
III. $O_2^{2-}$ has a shorter bond length than $O_2$. Then which of the following is correct?

• A. I only
• B. II and III
• C. I and II
• D. I II and III

Answer 1

Answer: (C)

Bond order of $N_2{}^{+}$ is 2.5 and that of $N_2$ is 3 . Hence former bond is weaker and longer. Bond order of $NO$ and $N{O}^{+}$ are 2.5 and 3 respectively. Bond order of $O_2^{2-}$ and $O_2$ are 1 and 2 respectively. Hence $O_2$ bond length must be shorter.