QJEEM19Chd66e: JEE Main 2019 Chemistry - Class 11 JEEM19Chd66e Solution: Among the following, the molecule expected to be stabilized by…

C₂ has 12 electrons.

Moleculer orbital configuration of C₂ is

${\sigma _{1{s^2}}}\,\sigma _{1{s^2}}^ * \,\,{\sigma _{2{s^2}}}\,\,\sigma _{2{s^2}}^ * \,\,{\pi _{2p_x^2}} =\,{\pi _{2p_y^2}}$

Bond order of C₂ = ${{8 - 4} \over 2}$ = 2

C₂^- has 13 electrons.

Moleculer orbital configuration of C₂^- is

${\sigma _{1{s^2}}}\,\sigma _{1{s^2}}^ * \,\,{\sigma _{2{s^2}}}\,\,\sigma _{2{s^2}}^ * \,\,{\pi _{2p_x^2}} =\,{\pi _{2p_y^2}}$ ${\sigma _{2p_z^1}}$

Bond order of C₂^- = ${{9 - 4} \over 2}$ = 2.5

As we know, higher is the bond order more will be the stability of the molecule.

So we can say, stability of C₂ increases when it forms C₂^- ion.