Question

The bond order and the magnetic characteristics of $C{N^ - }$ :
A.3, diamagnetic
B.$2\dfrac{1}{2}$ , diamagnetic
C.$2\dfrac{1}{2}$ , paramagnetic
D.3, diamagnetic

Answer 1

Hint:The bond order is found by the bonding electron and non- bonding electron. The magnetic characteristics of $C{N^ - }$ is the MOT concept. The number of bonds between a pair of atoms is called the bond order. Which electrons are paired in diamagnetic repelled by both poles of magnetic. That have one or more unpaired electrons are paramagnetic and attracted to a magnetic field.

Complete step by step answer:
$C{N^ - }$ has 14 electrons which are similar to that of nitrogen molecules. Due to the MOT concept, Nitrogen molecules are diamagnetic. All the electrons are paired. Bond order finds by the bonding and antibonding electrons. All the electrons are paired, this ion should be diamagnetic.
B.O. $ = \dfrac{1}{2}\left[ {{N_b} - {N_a}} \right]$
         $ = \dfrac{1}{2}\left[ {8 - 2} \right]$
       =3.
According to MOT,
 $C{N^ - } = \sigma _{1s}^2,\sigma _{1s}^{*2},\sigma _{2s}^2,\sigma _{2s}^{*2},\pi _{2px}^2 = \pi _{2py}^2,\sigma _{2pz}^2$
Due to electron arrangement its magnetic characteristic is diamagnetic.
Hence, option (A) is the correct answer.
The bond order of $C{N^ - }$ is 3 and the magnetic property of $C{N^ - }$ is diamagnetic.

Additional information:
The number of bonds between a pair of atoms is called the bond order. The magnetic properties of substances can be determined by examining its electron configuration which is characterized by bonding and antibonding electrons.

Note:Here we must remember about bonding and antibonding electrons. The orbitals are fulfilled by an electron and unfilled electrons form the number of bonds. Magnetic properties constitute supplementary information to support other data. Magnetic property defined by the filled electrons in the orbitals.