Question

Given below are two statements:

Statement I: Experimentally determined oxygen-oxygen bond lengths in the \( O_2 \) are found to be the same and the bond length is greater than that of a \( O=O \) (double bond) but less than that of a single \( O-O \) bond.

Statement II: The strong lone pair-lone pair repulsion between oxygen atoms is solely responsible for the fact that the bond length in ozone is smaller than that of a double bond \( O=O \) but more than that of a single bond \( O-O \).

In light of the above statements, choose the correct answer from the options given below:

• A. Statement I is true but Statement II is false
• B. Statement I is false but Statement II is true
• C. Both Statement I and Statement II are false
• D. Both Statement I and Statement II are true

Hint:

In molecules like ozone, resonance structures and lone pair interactions can significantly affect bond lengths and angles, deviating from simple bond theory predictions.

Answer 1

The Correct Option is D

- Statement I is true: The oxygen-oxygen bond length in \( O_2 \) is indeed greater than a double bond \( O=O \) but less than a single \( O-O \) bond.
- Statement II is also true: In ozone, the bond length is affected by lone pair-lone pair repulsion, which is greater than in \( O=O \) bonds, leading to a slightly longer bond in ozone.

Final Answer: Both Statement I and Statement II are true.

Answer 2

Step 1: Understand Statement I.
Statement I states that the experimentally determined oxygen-oxygen bond length in \( O_2 \) is found to be the same in both bonds, and that this bond length is greater than that of a \( O=O \) (double bond) but less than that of a single \( O-O \) bond.
This is correct. In the \( O_2 \) molecule, the bond length is a result of the resonance between the two contributing structures: one with a double bond and one with a single bond. As a result, the actual bond length is intermediate between the \( O=O \) (double bond) and \( O-O \) (single bond). This is consistent with the bond length observed experimentally for \( O_2 \).

Step 2: Understand Statement II.
Statement II claims that the strong lone pair-lone pair repulsion between oxygen atoms is solely responsible for the bond length in ozone being smaller than that of a double bond \( O=O \) but larger than that of a single bond \( O-O \).
This statement is also true. In ozone (\( O_3 \)), the lone pairs on the oxygen atoms create repulsion, which affects the bonding. This repulsion contributes to the bond length being longer than the \( O=O \) double bond but shorter than the \( O-O \) single bond. The presence of lone pairs on the oxygen atoms leads to a bond order between that of a single and double bond.

Step 3: Conclusion.
Both Statement I and Statement II are true. Statement I accurately describes the bond length in \( O_2 \), and Statement II correctly explains the bond length in ozone due to lone pair-lone pair repulsion.

Final Answer:
\[ \boxed{\text{Both Statement I and Statement II are true.}} \]