Question

Oxygen molecule is paramagnetic in nature. What is the paramagnetic content in terms of magnetic moment in $O_2^{-}$?

• A. $1.732$
• B. $3$
• C. $1.5$
• D. $2.5$

Answer 1

Answer: (A)

$O_2^{-}:\left(\sigma 1s^2\right)\left({\sigma }^{\ast }1s^2\right)\left(\sigma 2s^2\right)\left({\sigma }^{\ast }2s^2\right)\left(\sigma 2P_z^2\right)$
$\left(\pi 2p_x^2=\pi 2p_y^2\right)\left({\pi }^{\ast }2p_x^2={\pi }^{\ast }2p_y^1\right)$
$O_2^{-}$ has $1$ unpaired electron.
$\mu =\sqrt{n\left(n+2\right)}B.M.$
$=\sqrt{1\left(1+2\right)}=\sqrt{3}$
$=1.732B.M.$