Question

In the following question, Assertion (A) is given followed by a statement of Reason (R). Choose the correct answer.
Assertion (A): \(\pi (2p_{z}), \pi (2p_{y}), \pi^{*} (2p_{z}), \pi^{*} (2p_{y})\) molecular orbitals have one nodal plane each.
Reason (R): All the molecular orbitals formed by the sideways overlapping have one nodal plane.

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

Hint:

When evaluating assertions and reasons, always ensure the reason directly explains the assertion. A true reason does not necessarily provide a valid explanation.

Answer 1

The Correct Option is B

- Assertion (A): The given molecular orbitals (\(\pi (2p_{z})\), \(\pi (2p_{y})\), \(\pi^{*} (2p_{z})\), and \(\pi^{*} (2p_{y})\)) all have one nodal plane. This is correct because the \(\pi\) and \(\pi^{*}\) orbitals formed by the sideways overlapping of atomic orbitals always have one nodal plane between the nuclei. These orbitals involve lateral (sideways) overlap and create a single node in between, leading to the formation of bonding and anti-bonding molecular orbitals. - Reason (R): The reason states that "All the molecular orbitals formed by the sideways overlapping have one nodal plane." While this is true for the \(\pi\) and \(\pi^{*}\) molecular orbitals formed by sideways overlap, this reason does not correctly explain the assertion. The assertion specifically refers to the \(\pi\) and \(\pi^{*}\) molecular orbitals, while the reason is more generalized and applies to all sideways overlapping molecular orbitals, which is not specific to the assertion made. Therefore, the assertion is true, but the reason is not the correct explanation of the assertion, making the correct answer (B)