82. NATURE OF CHEMICAL BONDING (29)- Covalent Bonding(28) – Molecular Orbital Theory(3)- LCAO approximation(1).

  LINEAR COMBINATION OF ATOMIC ORBITALS (LCAO approximation)     MOT is incorporated in quantum mechanics.  As we have already discussed that classical physics (physics related to macroscopic things e.g.  gravity , acceleration etc applied to everyday objects )and quantum mechanics( physics related to microscopic things e.g.sub atomic particles) are two very different approaches. So,…

79. NATURE OF CHEMICAL BONDING (26)- Covalent Bonding(25) – Problems(2).

Q: Which of the following statements for bond angles (θ) in CH4 and CH2F2 molecules is true – A] θ CH4  >  θ CH2F2 B] θ CH4 < θ CH2F2 C] θ CH4 = θ CH2F2 A: Both molecules are sp3 hybridized . We know that bond angle in methane is 109.5º . To predict the bond angle in difluoromethane i.e CH2F2 molecule , we apply…

76. NATURE OF CHEMICAL BONDING (23)- Covalent Bonding(22) – Drago Rule (1).

In this post, we will study yet another rule ,which is important while studying hybridization in molecules. This rule was stated to explain certain observations , which could not be explained by hybridization theory alone. Why is Drago rule needed? 1] To explain anomalous observations in bond angles of Group 15 and 16 hydrides- Group 15 elements…

74. NATURE OF CHEMICAL BONDING (21)- Covalent Bonding(20)- Bent’s rule(3).

Example 3 – PCl3F2 molecule .  This molecule has TBP geometry with two F atoms and three Cl atoms as substituents.According to Bent’s rule – F atoms are more electronegative and so they will prefer the axial position , where there is no s-character (less electronegative).The three Cl atoms will occupy the equatorial positions. Thus,…