Question

The correct order in which the O—O bond length increases in the following is:

• A. H₂O₂<O₂<O₃
• B. O₃<H₂O₂<O₂
• C. O₂<O₃<H₂O₂
• D. O₂<H₂O₂<O₃

Answer 1

The Correct Option is C

To determine the correct order of increasing O—O bond lengths among different oxygen-containing compounds, we need to understand the nature of the bonds in each of these molecules:

1. **O₂ (Oxygen Molecule)**: O₂ is a diatomic molecule with a double bond between the two oxygen atoms. The O—O bond length in O₂ is relatively short due to the presence of a double bond. The typical bond length for O₂ is approximately 121 pm.
2. **O₃ (Ozone)**: Ozone has a resonance structure, which includes a single bond and a double bond. The effective bond order is between that of a single and a double bond due to resonance. This gives an average bond length that is longer than a double bond but shorter than a single bond. Typically, the O—O bond length in ozone is about 128 pm.
3. **H₂O₂ (Hydrogen Peroxide)**: In hydrogen peroxide, each O atom is bonded to another O atom by a single bond. Single bonds are generally longer than double bonds. Thus, the O—O bond length in H₂O₂ is around 147 pm.

By comparing the bond lengths, we can establish the order:

1. **O₂** with the shortest bond length due to the double bond.
2. **O₃** with a longer bond length due to resonance.
3. **H₂O₂** with the longest bond length due to the single bond.

Thus, the correct order of increasing O—O bond lengths is:

O_2 < O_3 < H_2O_2