2023 Manipur Chemical Bonding and Molecular StructureMolecular Orbital Theory Medium Question 3 of 20 in Molecular Orbital Theory

Which one of the following statements is incorrect related to Molecular Orbital Theory?

A The $\pi^*$ antibonding molecular orbital has a node between the nuclei.
B In the formation of bonding molecular orbital, the two electron waves of the bonding atoms reinforce each other.
C Molecular orbitals obtained from $2P_x$ and $2P_y$ orbitals are symmetrical around the bond axis.
D A $\pi$-bonding molecular orbital has larger electron density above and below the internuclear axis.

The answer is C.

Solution

Molecular orbitals formed from $2P_x$ and $2P_y$ orbitals (perpendicular to the bond axis, typically taken as the z-axis) are actually unsymmetrical (not symmetrical) around the bond axis — they form $\pi$ molecular orbitals with electron density above and below the axis, not symmetric around it. So this statement is incorrect.

Concept Molecular Orbital Theory

Molecular Orbital Theory in past papers

20 questions from this chapter have appeared across 13 exam years.