Question

The bond order of ${\mathrm{O}}_2$ is?

• A. $1$
• B. $2$
• C. $1.5$
• D. $3$

Answer 1

The correct option is B

$2$

Explanation for the correct option:

Option(B): $2$

• Bond order is defined as the number of bonds present in a given molecule.
• The valence electrons of Oxygen is $6$ , for which the electronic configuration can be shown as:-$\mathrm{O}=$ $1\mathrm{s}²2\mathrm{s}²2\mathrm{p}⁴$
• Atomic orbitals of Oxygen basically combine to form molecular orbitals, hence the MO diagram of Oxygen can be shown as:

• From the figure, we can see that for Oxygen the number of bonding electrons $=10$and the number of anti-bonding electrons is $=4$
• Bond order in Oxygen molecule can be calculated by putting the bond order formula as:

$$\begin{gathered} \mathrm{B}.\mathrm{O}=\frac{(\mathrm{Number}of\mathrm{bonding}\mathrm{electrons}–\mathrm{Number}\mathrm{of}\mathrm{antibonding}\mathrm{electrons})}{2} \\ =\frac{10–6}{2} \\ =2 \end{gathered}$$

Hence, The bond order of ${\mathrm{O}}_2$ is $2$.