Question

According to MOT (Molecular Orbital Theory), the molecular orbitals are formed by mixing of atomic orbitals through LCAO (linear combination of atomic orbitals). The correct statement(s) about molecular orbitals is/are:
Statement (a): bonding of molecular orbitals are formed by the addition of wave-functions of atomic orbitals of the same phase.
Statement (b): anti-bonding molecular orbitals are formed by subtraction of wave-functions of atomic orbitals of the same phase.
Statement (c): non-bonding molecular orbitals do not take part in bond formation because they belong to inner shells.
Statement (d): anti-bonding molecular orbitals provide stability to molecules while bonding molecular orbitals make the molecules unstable.

• A. Statement a, d
• B. Statement a, b, c
• C. Statement a, b , d
• D. Statement a, b

Answer 1

Answer: (B)

Statement a, b, c

When the wave functions of same phase are added, bonding molecular orbitals are obtained.
When wave functions of same phase are subtracted, anti bonding molecular orbitals are obtained.
The non-bonding molecular orbitals do not take part in bond formation because they belong to inner shells and they do not overlap significantly.
The bonding molecular orbitals provide stability to molecules while anti bonding molecular orbitals make the molecules unstable.