Bond disassociation energy refers to amount of energy required to break bonds of one mole of atom of particular type whereas lattice energy is the energy required to separate a crystal lattice containing one mole ions into their respective gaseous states.

What i can understand from the above information is that bond dissociation energy has to be a broader classification and lattice energy must be a subset of it.

Is it true or am i wrong. Please correct me, i am a bit confused. Any help would be appreciated.

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    $\begingroup$ Why are you speaking of ionic compounds, to begin with? Both terms are much broader than that. $\endgroup$ May 7, 2020 at 9:26
  • $\begingroup$ What do you mean? $\endgroup$ May 7, 2020 at 9:30
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    $\begingroup$ I mean just that. Bond disassociation energy is not limited to ionic compounds. Neither is lattice energy. $\endgroup$ May 7, 2020 at 9:54
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    $\begingroup$ if you are a senior secondary student (class 11 or 12) like me, then my point may mean some sense-bond disassociation enthalpy is the energy required to break a bond between two atoms of the same molecule while lattice enthalpy is the energy required to overcome the intermolecular forces of attraction between the molecules in a crystalline system ( it may be an ionic or covalent or molecular crystal as @Ivan Neretin quoted. $\endgroup$
    – KaBe2003
    May 7, 2020 at 11:50

1 Answer 1


Well if you want the simplest answer, it is:

Lattice energy is used when talking about ionic bonds where all the molecules are neatly arranged in a 3D structure called crystal lattice.

Bond enthalpy/Bond dissociation energy is used when talking about covalent bonded molecules where there is no formation of 3D structures (crystal lattice). The molecules are held together by VanderWaal forces.

Both the terms are almost similar and both are independent (not subset of each other). When talking about lattice energy we specifically convey that the energy required to break the ionic bonds i.e breaking the lattice. In bond dissociation energy we are breaking the covalent bonds (there is no such breakage of structures)

  • $\begingroup$ both concepts can be used for ionic and covalent compounds, Bond dissociation regards describes the behaviour of an isolated molecule (.i.e. in gas phase or in solution) while the second concepts is useful to describe the behaviour of the molecule in a crystal structure. Usually this magnitude is used in the Born-Haber cycle for ionic crystals since it is easy to understand. Thats good for a General Chemistry course, but to narrow a concept when you try to understand more complex systems. $\endgroup$
    – PAEP
    Apr 2 at 20:01
  • $\begingroup$ @PAEP Hmm, in the book which i use, there under the definition of lattice energy it is specifically mentioned "one mole of a solid ionic compound". However i don't deny your claim outrightly. Anyways thinking too critically in a subject like chemistry just fries my grey matter. $\endgroup$
    Apr 3 at 10:13

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