JEE MAIN - Chemistry (2014 (Offline) - No. 21)
Which one of the following properties is not shown by NO?
It combines with oxygen to form nitrogen dioxide
It’s bond order is 2.5
It is diamagnetic in gaseous state
It is a neutral oxide
Vysvetlenie
Nitric oxide is paramagnetic in the gaseous state because of the presence of one unpaired electron in its outermost shell.
The electronic configuration of $$NO$$ is
$$\sigma _{1s}^2\,\sigma _{1s}^{ * 2}\,\sigma _{2s}^2\,\sigma _{2s}^{ \circ 2}\,\sigma _{{2_{{p_z}}}}^2\,\pi _{{2_{{p_x}}}}^2$$
$$ = \pi _{{2_{Py}}}^2\,\pi _{{2_{Px}}}^{ * 1}$$
The electronic configuration of $$NO$$ is
$$\sigma _{1s}^2\,\sigma _{1s}^{ * 2}\,\sigma _{2s}^2\,\sigma _{2s}^{ \circ 2}\,\sigma _{{2_{{p_z}}}}^2\,\pi _{{2_{{p_x}}}}^2$$
$$ = \pi _{{2_{Py}}}^2\,\pi _{{2_{Px}}}^{ * 1}$$