Chapter 14, Problem 1DQ

Interpretation Introduction

Interpretation:

The molecular orbitals should be stated. The comparison of molecular orbitals with atomic orbitals should be predicted. Whether the shape of the bonding orbital and antibonding orbitals could be suggested which has lower energy should be predicted.

Concept Introduction:

Molecular orbital theory is a method that shows that how atomic orbitals combine with other or with each other to form bonding and antibonding orbitals. It is used to determine the molecular structure of a molecule.

Answer to Problem 1DQ

The mathematical function that describes wave nature of the electron within a molecule is known as molecular orbital. Two atomic orbitals are combined to form two molecular orbitals with different energies. The energy of the bonding molecular orbital is low in energy and can be predicted by its shape.

Explanation of Solution

The mathematical function that describes wave nature of the electron within a molecule is known as molecular orbital. It is used to predict the probability of finding the electrons in an atom. The molecule orbital is divided into bonding and antibonding molecular orbitals.

The comparison of MO and AO are mentioned below:

• Two atomic orbital combine to form two types of molecular orbital; bonding and antibonding.
• Bonding molecular orbitals are produced by the additive combination of atomic orbitals whereas antibonding molecular orbitals are produced by the subtractive combinationof atomic orbitals.
• Bonding orbital is represented by $\sigma$ and has less energy than antibonding molecular orbitals.
• Antibonding orbital is represented by ${\sigma }^{*}$ and has more energy than bonding molecular orbitals.

Bonding orbital has low energy as these are present at the ground state while antibonding orbitals are present at excited state. These orbitals have high energy and are unstable. The energy of the bonding molecular orbitals can be predicted by their shape as shown below:

  

The figure is the molecular orbital diagram of H₂. The shape of bonding molecular orbital is different from the antibonding molecular orbital. Therefore, the energy of the bonding molecular orbital is low in energy and can be predicted by its shape.

Conclusion

The mathematical function that describes wave nature of the electron within a molecule is known as molecular orbital. Two atomic orbitals are combined to form two molecular orbitals with different energies. The energy of the bonding molecular orbital is low in energy and can be predicted by its shape.