Question

Among the following species, identify the pair having same bond order $ C{{N}^{-}},O_{2}^{-},N{{O}^{+}},C{{N}^{+}} $

• A. $ C{{N}^{-}} $ and $ O_{2}^{-} $
• B. $ O_{2}^{-} $ and $ N{{O}^{+}} $
• C. $ C{{N}^{-}} $ and $ N{{O}^{+}} $
• D. $ C{{N}^{-}} $ and $ C{{N}^{+}} $
• E. $ N{{O}^{+}} $ and $ C{{N}^{+}} $

Answer 1

Answer: (C)

Species having the same number of electrons, have same bond order.

Since, $ C{{N}^{-}} $ and $ N{{O}^{-}} $ have same number of electrons, they have same bond order, ie, 3.
$ C{{N}^{-}} $ or $ N{{O}^{+}}=14=\sigma 1{{s}^{2}},{{\sigma }^{*}}1{{s}^{2}},\sigma 2{{s}^{2}},{{\sigma }^{*}}2{{s}^{2}}, $
$ \sigma 2p_{z}^{2},\pi 2p_{x}^{2}\approx \pi 2p_{y}^{2} $
Bond order $ =\frac{{{N}_{b}}-{{N}_{a}}}{2}=\frac{10-4}{2}=3 $