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Mass and chemical reactions

  1. Aug 20, 2008 #1
    Does mass of compounds change due to exothermic/endothermic chemical reactions?
     
  2. jcsd
  3. Aug 20, 2008 #2

    malawi_glenn

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    This is not the chemistry sub-forum *hint* ;-)
     
  4. Aug 20, 2008 #3

    mathman

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    Yes but. The difference in mass is undetectable by almost all instruments.
     
  5. Aug 21, 2008 #4
    Chemically, the answer is definitely NOT, that's why I ask here.
     
  6. Aug 21, 2008 #5

    malawi_glenn

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    Well chemistry processes are that the electrons are chaning orbits, so that their binding energy is released or increased -> which influences the mass of the system under consideration. It is the EM- force analogy with fusion and fission in Nuclear physics.

    But the binding energies of electrons in atoms and molecules are of the order eV (!) so it is very tiny mass defect, just as mathman said.
    The binding energies in nuclei are of the order MeV, so there the consequenses are bigger.
     
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