The molecular orbit is preferred over valence bond theory. Why ?
Answers
Answer:
MO theory actually predicts electron transitions because of the differences in the energy levels of orbitals in the molecule. MO theory has been more correct in numerous instances and for this reason it is preferred. Valence Bond theorydescribes covalent bond formation as well as the electronic structure of molecules.
Answer:
Hybridization theory is a qualitative theory, intended to give generalized results that agree well with experiment but do not require any sophisticated calculation. Molecular orbital theory on the other hand, is generally designed to produce quantitative results and requires some degree of sophisticated calculation. Hybridization generally does well when discussing smaller molecules and ions, agrees generally with the geometry and shape of the molecule, and can be used to predict some of the properties of a molecule. Molecular orbital theory can be used to actually calculate many of the properties of a molecule, from bond strengths, distances, ionization potentials, spectra, conjugation, and the like.
It’s not “preferable”- both have important uses, but in general, if you are going to go through the trouble of getting molecular orbital results, there’s little need to use the less sophisticated and more qualitative hybridization theory. Furthermore, there’s no reason that molecular orbital theory can’t be used to generate hybrid orbitals- as abelian solutions to the hamiltonian, linear combinations of orbitals are also valid solutions to the hamiltonian. The utility of such a solution or derivation, though, is questionable.