Question

The pairs of species of oxygen and their magnetic behaviours are noted below. Which of the following presents the correct description ?

• A. $O,O_2^{2-}$ - Both paramagnetic
• B. $O_2^{-},O_2^{2-}$ - Both diamagnetic
• C. $O^{+},O_2^{2-}$ - Both paramagnetic
• D. $O_2^{+},O_2$ - Both paramagnetic

Answer 1

Answer: (D)

$O_2^{+}=KK\sigma 2s^2{\sigma }^{\ast }2s^2\sigma 2p_z^2(\pi 2p_x^2=\pi 2p_y^2)({\pi }^{\ast }2p_x^1)$
$O_2=KK\sigma 2s^2{\sigma }^{\ast }2s^2\sigma 2p_z^2(\pi 2p_x^2=\pi 2p_y^2)({\pi }^{\ast }2p_x^1={\pi }^{\ast }2p_y^1)$
$O_2$ and $O_2^{+}$ contain unpaired electron in ${\pi }^{\ast }$ ABMO so paramagnetic.