Chemical Bonding and Molecular Structure — JEE Advanced · 2022 · 28 Aug 2022 · Paper 1 Question with Solution

For diatomic molecules, the correct statement(s) about the molecular orbitals formed by the overlap to two

2 p_{z}

orbitals is(are)

(A) $σ$ orbital has a total of two nodal planes.✓ Correct
(B) $σ^{*}$ orbital has one node in the $x z$ -plane containing the molecular axis.
(C) $π$ orbital has one node in the plane which is perpendicular to the molecular axis and goes through the center of the molecule.
(D) $π^{*}$ orbital has one node in the $x y$ -plane containing the molecular axis.✓ Correct

Answer: (A), (D)

Solution

For

2 p_{z}

orbital overlap:

(A) The

σ

bonding orbital formed has two nodal planes (the

x y

and

x z

planes perpendicular to the molecular axis). Correct.

(B) The

σ^{*}

antibonding orbital has one nodal plane perpendicular to the molecular axis (between the nuclei), not in the

x z

-plane containing it. Incorrect.

(C) The

π

bonding orbital has one nodal plane containing the molecular axis, not perpendicular to it. Incorrect.

(D) The

π^{*}

antibonding orbital has one nodal plane (the

x y

-plane) containing the molecular axis. Correct.

JEE Advanced · 2022 · 28 Aug 2022 · Paper 1 · One or more correct options