Question

Assertion: $C{O}_2$ is a resonance stabilized molecule.
Reason: The bond length of $C-O$ in $C{O}_2$ is in between the lengths of a single and a double bond.

• A. Both the assertion and the reason are true and the reason is the correct explanation of the assertion.
• B. Both the assertion and the reason are true but the reason is not the correct explanation of the assertion.
• C. The assertion is true but the reason is false.
• D. Both the assertion and the reason are false.

Answer 1

The correct option is C The assertion is true but the reason is false.

When a molecule cannot be adequately described by a single
classical structure, the concept of resonance is often invoked.

Thus, $C{O}_2$ molecule is described as a resonance hybrid of the following structures:

The bond lengths in carbon dioxide molecule lies between those of a normal C-O double bond (121 pm) and a C-O triple bond (110 pm). It is around 115 pm in $C{O}_2$. This can be explained by considering the hybrid of the resonance structures shown above.

Hence here, the assertion is true but the reason is not.