Q. The number of antibonding electron pairs in $O_{2}^{2 -}$ molecular ion on the basis of molecular orbital theory is (Atomic number of O is 18.)
A) 5
B) 4
C) 3
D) 2
Explanation
(b)
The electronic configuration of $O_{2}^{2 -}$ ion is
$O_{2}^{2 -} - \sigma 1s^{2},\ _{\sigma}^{*}1s^{2}\ \sigma 2s^{2},\ _{\sigma}^{*}2s^{2},\sigma 2p_{z}^{2}\ ,\ \pi 2p_{x}^{2},\pi 2p_{y}^{2},\ \ _{\pi}^{*}2p_{x}^{2},\ _{\pi}^{*}2p_{y}^{2}\$
Hence, number of antibonding electron pair in $O_{2}^{2 -}$ molecular ion are four.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.