Question

The cynide ion and $N_2$ are iso electronic but in contrast to $C{N}^{-}$,$N_2$ is inert because:

• A. low bond energy
• B. absence of bond polarity
• C. unsymmetrical electron distribution
• D. presence of more no. of electrons in bonding orbitals.

Answer 1

Answer: (B)

absence of bond polarity

Both $C{N}^{-}$ and $N_2$ molecules have the same $MO$ diagrams but differ only in bond polarity.

$C{N}^{-}$ ion is reactive due to presence of bond polarity.

While $N_2$ is inert due to absence of bond polarity.

Hence b is the correct answer.