Question

Assertion : Bonding molecular orbital has greater stability than corresponding antibonding molecular orbital.
Reason : The electron density in a bonding molecular orbital is located away from the space between the nuclei
while in antibonding molecular orbital it is located between the nuclei of the bonded atoms

Answer 1

Answer:

Assertion is correct, reason is incorrect.

In the bonding molecular orbital (MO) of H

2

electron density is increased between the nuclei. The bonding MO is ψ

A

+ ψ

B

which shows constructive interference of the combining electron waves.

Hence, the assertion is correct, reason is incorrect.

Answer 2

A is true, but R is false.

Since bonding molecular orbital has lower energy and hence greater stability than the corresponding antibonding molecular orbital.

And, In the bonding molecular orbital (MO) of $H_2$  electron density is increased between the nuclei. The bonding MO is ψA + ψB which shows constructive interference of the combining electron waves.

Also, Electrons that spend most of their time between the nuclei of two atoms are placed into the bonding orbitals, and electrons that spend most of their time outside the nuclei of two atoms are placed into antibonding orbitals. This is because there is an increase in electron density between the nuclei in bonding orbitals and a decrease in electron density in antibonding orbitals. Placing an electron in the bonding orbital stabilizes the molecule because it is in between the two nuclei. Conversely, placing electrons into the antibonding orbitals will decrease the stability of the molecule. Electrons will fill according to the energy levels of the orbitals. They will first fill the lower energy orbitals, and then they will fill the higher energy orbitals. If a bond order of zero is obtained, that means that the molecule is too unstable and so it will not exist.

Hence, the assertion is correct, reason is incorrect.