Question

Which of the following statements are correct?
I. Bond order of $NO$ is $2.5$
II. Bond order of $N{O}^{+}$is $3.0$
III. Bond order of $O_2$ is $1.5$
IV. Bond order of $CO$ is $3.0$

• A. I, II, III
• B. II, III, IV
• C. I, II, IV
• D. II, IV

Answer 1

Answer: (C)

$NO=15=\sigma 1s^2,{\sigma }^{\ast }1s^2,\sigma 2s^2,{\sigma }^{\ast }2s^2,\sigma 2p_z^2,\sigma 2p_x^2=\pi 2p_y^2,\pi 2p_x{}^1$
B.O $=\frac{10-5}{2}=2.5$
$N{O}^{+}=14=\sigma 1s^2,{\sigma }^{\ast }1s^2,\sigma 2s^2,{\sigma }^{\ast }2s^2,\sigma 2p_z^2,\sigma 2p_x^2=\pi 2p_y^2,\pi 2p_x^2,{\pi }^{\ast }2p_x{}^0$
B.O $=\frac{10-4}{2}=3$
$O_2=16=\sigma 1s^2,{\sigma }^{\ast }1s^2,\sigma 2s^2,{\sigma }^{\ast }2s^2,\sigma 2p_z^2,\pi 2p_x^2=\pi 2p_y^2,\pi 2p_x{}^0$
B.O $=\frac{10-6}{2}=2$
$CO=14=\sigma 1s^2,{\sigma }^{\ast }1s^2,\sigma 2s^2,{\pi }^{\ast }{2}_x^2=\pi 2p_y^2,\sigma 2p_z^2,{\sigma }^{\ast }2p{s}^2$
B.O $=\frac{10-4}{2}=3$