JEE Main 2017 — Chemistry Inorganic Chemistry

CO has no unpaired electron while other have unpaired electrons so, paramagnetic in nature.(Apply M.O.T)

$$\text{Molecular orbital configuration}\Rightarrow$$Molecular orbital configuration⇒

$$\text{CO }:{\text{like N}}_{2} ;\text{ σ}1{s}^{2}<{\text{σ}}^{*}{\text{1S}}^{2}<\text{σ}2{\text{S}}^{2}<{\sigma }^{*}2{\text{S}}^{2}<\text{π}2{\text{P}}_{\text{x}}^{2}\text{= π}2{\text{P}}_{\text{y}}^{2}<\text{σ}2{\text{P}}_{\text{z}}^{2} (\text{No unpaired electrons)}$$CO :like N2​; σ1s2<σ∗1S2<σ2S2<σ∗2S2<π2Px2​= π2Py2​<σ2Pz2​(No unpaired electrons)

$${\text{O}}_{2} :\text{σ}1{\text{S}}^{2}<{\text{σ}}^{*}{\text{1S}}^{2}<\text{σ}2{\text{S}}^{2}<{\text{σ}}^{*}2{\text{S}}^{2}<\text{σ}2{\text{P}}_{\text{z}}^{2}<\text{π}2{\text{P}}_{\text{x}}^{2}=\text{π}2{\text{P}}_{\text{y}}^{2}<{\text{π}}^{*}2{\text{P}}_{\text{x}}^{\text{1}}\text{= }{\pi }^{*}2{\text{P}}_{\text{y}}^{\text{1}} (2\text{unpaired electrons})$$O2​:σ1S2<σ∗1S2<σ2S2<σ∗2S2<σ2Pz2​<π2Px2​=π2Py2​<π∗2Px1​= π∗2Py1​(2unpaired electrons)

$${\text{B}}_{2}:\text{σ}1{\text{S}}^{2}<{\text{σ}}^{*}1{\text{S}}^{2}<\text{σ}2{\text{S}}^{2}<{\text{σ}}^{*}2{\text{S}}^{2}<\text{π}2{\text{P}}_{\text{x}}^{1}=\text{π}2{\text{P}}_{\text{y}}^{\text{1}} (2\text{unpaired electrons})$$B2​:σ1S2<σ∗1S2<σ2S2<σ∗2S2<π2Px1​=π2Py1​(2unpaired electrons)

$$\text{NO }: \text{σ}1{\text{S}}^{2}<{\text{σ}}^{*}1{\text{S}}^{2}<\text{σ}2{\text{S}}^{2}<{\text{σ}}^{*}2{\text{S}}^{2}<\text{σ}2{\text{P}}_{\text{z}}^{2}<\text{π}2{\text{P}}_{\text{x}}^{2}=\text{π}2{\text{P}}_{\text{y}}^{2}<{\text{π}}^{*}2{\text{P}}_{\text{y}}^{\text{1}}={\text{ π}}^{*}2{\text{P}}_{\text{x}}^{0}(1\text{unpaired electrons})$$NO :σ1S2<σ∗1S2<σ2S2<σ∗2S2<σ2Pz2​<π2Px2​=π2Py2​<π∗2Py1​= π∗2Px0​(1unpaired electrons)