Question

difference between vbt and cft​

Answer 1

Answer:

The term VBT stands for valence bond theory. It is a theory used to describe the formation of different chemical bonds between atoms. This theory explains the overlapping or mixing of atomic orbitals to form chemical bonds. The term CFT stands for Crystal field theory. It is a model that is designed to explain the breaking of degeneracies (electron shells of equal energy) of electron orbitals (usually d or f orbitals) due to the static electric field produced by a surrounding anion or anions (or ligands). The key difference between VBT and CFT is that VBT explains the mixing of orbitals whereas CFT explains the splitting of orbitals.

Answer 2

Dear Student,

● Valence bond theory (CFT) -

• Valence bond theory explains chemical bonding of half-filled atomic orbitals.

● Postulates of valence bond theory -

1. Valence orbitals of atom overlap each other to form a bond.
2. A pair electrons is present in overlapping orbitals.
3. Electron density is maximum around bonded atoms.
4. Degree of overlapping determines strength of the bond.

● Crystal field theory (CFT) -

• It describes the breaking of orbital degeneracy in transition metal complexes due to the presence of ligands.

● Postulates of crystal field theory -

1. Metal ion and ligands are considered point charges.
2. These interact by ionic (electrostatic) bonding.
3. Ligands can be either negative point charges or neutral dipoles.
4. Central metal ion is surrounded by ligands with 1/more lone pairs of electrons.
5. There is no orbital overlap between metal ion and ligand.

Hope this helps you...