Chemical Bonding And Molecular Structure Ques 10
10. The pairs of species of oxygen and their magnetic behaviours are noted below. Which of the following presents the correct description?
[2011 M]
(a) $O_2^{-}, O_2^{2-}-$ Both diamagnetic
(b) $O^{+}, O_2^{2-}-$ Both paramagnetic
(c) $O_2^{+}, O_2-$ Both paramagnetic
(d) $O, O_2^{2-}-$ Both paramagnetic
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Answer:
Correct Answer: 10.(c)
Solution:
(c) MOT configurations of $O_2$ and $O_2^{+}$:
$O_2^+:(\sigma 1 s)^2(\sigma^* 1 s)^2(\sigma 2 s)^2(\sigma^* 2 s)^2(\sigma 2 p_z)^2$
$(\pi 2 p_x^2=\pi 2 p^2)(\pi^* 2 p_x{ }^1=\pi^* 2 p^1 _{y})$
Number of unpaired electrons $=2$, so paramagnetic.
$O_2:(\sigma 1 s)^2 (\sigma^* 1 s)^2 (\sigma 2 s)^2 (\sigma^* 2 s)^2 (\sigma 2 p_z)^2$
$(\pi 2 p^{2}=\pi 2 p^{2} _{y})(\pi * 2 p_x{ }^{1}=\pi * 2 p^{0} _{y})$
Number of unpaired electrons $=2$, so paramagnetic.
BETA
