The correct order in which the $\mathrm{O}-\mathrm{O}$ bond length increases in the following is:

• A

  $\mathrm{O}_2 < \mathrm{H}_2 \mathrm{O}_2 < \mathrm{O}_3$
• B

  $\mathrm{O}_3 < \mathrm{H}_2 \mathrm{O}_2 < \mathrm{O}_2$
• C

  $\mathrm{H}_2 \mathrm{O}_2 < \mathrm{O}_2 < \mathrm{O}_2$
• Correct answer
  D

  $\mathrm{O}_2 < \mathrm{O}_3 < \mathrm{H}_2 \mathrm{O}_2$

Solution

The bond Length decreases with increase of bond order which is the multiplicity of bond. If $\mathrm{BO}$ is 1 its a single bond; 2 for double bond and 3 for triple bond. The bond length of $\mathrm{O}-\mathrm{O}$ in $\mathrm{H}_2 \mathrm{O}_2$ is 147.5pm, in $\mathrm{O}_3$ is $128 \mathrm{pm}$ and in $\mathrm{O}_2$ it is $121 \mathrm{pm}$.

Hence, the correct answer is option: 'D'.