Summary of "Application of Molecular Orbital Theory (MOT) | B.Sc. semester and class 11th"

Summary of Main Ideas and Concepts

The video discusses the application of Molecular Orbital Theory (MOT) and its implications for understanding molecular stability, bond order, magnetic properties, and bond length. Key concepts include:

Stability of Molecules:
- The stability of a molecule can be assessed by examining the number of electrons in bonding and antibonding molecular orbitals.
- Electrons in bonding molecular orbitals (denoted as NB) contribute to stability, while those in antibonding molecular orbitals (denoted as NA) detract from it.
- A molecule is more stable if NB > NA.
bond order:
- bond order is calculated as:
  bond order = (NB - NA) / 2
- A positive bond order indicates stability, while a negative or zero bond order suggests instability or non-existence of the molecule.
Nature of Bonds:
- The bond order indicates the type of bond:
  - bond order = 1: single bond
  - bond order = 2: double bond
  - bond order = 3: triple bond
Magnetic Properties:
- A molecule is diamagnetic if all electrons are paired (no unpaired electrons).
- A molecule is paramagnetic if it contains one or more unpaired electrons, making it attracted to magnetic fields.
bond length:
- bond length is inversely related to bond order; higher bond order corresponds to shorter bond lengths.
- The bond length can be determined by comparing the bond orders of different molecules.

Assessing molecular stability:
- Count the electrons in bonding (NB) and antibonding (NA) molecular orbitals.
- If NB > NA, the molecule is stable; if NA > NB, it is unstable.
Calculating bond order:
- Use the formula:
  bond order = (NB - NA) / 2
- Interpret the bond order to determine the type of bond.
Determining Magnetic Properties:
- Identify the presence of unpaired electrons to classify the molecule as diamagnetic or paramagnetic.
Comparing Bond Lengths:
- Use bond order to compare bond lengths:
  - Higher bond order = shorter bond length.
  - Arrange molecules in order of increasing bond length based on their bond orders.