what differences can be noted of Quantum Chemistry and Basic Chemistry?

Discussion in 'Chemistry' started by Bishadi, Jan 1, 2009.

  1. Bishadi Banned Banned

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    2,745
    Since standard Chemical descriptions cannot confirm all experimental data, what are the primary reasons for using Quantum Chemistry and the descriptions described within a wave model?

    A wiki description:

     
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  3. Trippy ALEA IACTA EST Staff Member

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    What experimental data are you referring to here?

    Because it provides a more accurate description of structure and mechanism when comparing say Molecular Orbital Theory to VESPR theory.

    Many of the branches of chemistry referred to in that article are taught at high levels of chemistry - for example Molecular Orbital Theory (something i've mentioned several times) gets the most detail added to it at 3rd year level and above.
     
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  5. Bishadi Banned Banned

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    2,745
    and then you post
    wow!

    you really do not read what you write do you?

    basically you just said, 'the existing model is flawed so we use another theory that gives more accurate description in some frames'

    so now the next time i offer material that makes chemistry, basically extinct, perhaps be quiet and learn something before opening your keypad

    them differences share that chemistry needs work

    what i ask was why, and all you shared was generalization.

    this is not politics, but if you do not know why i will not be upset
     
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  7. Trippy ALEA IACTA EST Staff Member

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    10,890
    Molecular Orbital Theory is one aspect of Quantum Chemistry, it deals with explaining chemical interactions and moleculalr structures by looking at solutions to the schroedinger wave equation, and the way hybridized atomioc orbitals add together.

    Fronteir Molecular Orbital Theory is more accurate then say, Valence Shell Electron Pair Repulsion Theory which is a model for structure that was developed in the mid 50's, that essentially operates on the principle that electron pairs try get as far apart as possible because of electrostatic repulsion. This 'simplistic' idea accounts for the vast majority of structures we observe, but, there are some that it can not, for example, Strontium Flouride is bent where VSEPR predicts it should be linear, and Lithium Oxide is Linear where VSEPR predicts it should be bent.

    It's not that one is right, and the other is wrong. VSEPR is right in the sense that Newtonian Mechanics is correct. Essentially, Molecular Orbital Theory reduces to VSEPR in a lot of cases. VSEPR still gets taught in highschools, because FMO theory is too complicated, and VSEPR is accurate enough for most applications.

    ***Moderator Note***
    Continued abuse and name calling will not be tolerated. This forum is not the apporpriate place to initiate a flamewar.
     
  8. Bishadi Banned Banned

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    2,745
    in the original post, in the grey

    "In quantum mechanics the Hamiltonian, or the physical state, of a particle can be expressed as the sum of two operators, one corresponding to kinetic energy and the other to potential energy."

    It seems the definition you shared is talking about the mental idea of physical aspects other than the chemical potential.

    Why would the 'two operators' be important to chemistry?
     
  9. Bishadi Banned Banned

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    2,745
    Hey Trippy

    what happen to this thread?

    i was hoping to go over the operators to define that photon

    "In quantum mechanics the Hamiltonian, or the physical state, of a particle can be expressed as the sum of two operators, one corresponding to kinetic energy and the other to potential energy."
     
  10. Bishadi Banned Banned

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    2,745
    "In quantum mechanics the Hamiltonian, or the physical state, of a particle can be expressed as the sum of two operators, one corresponding to kinetic energy and the other to potential energy."
     

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