What is the difference between #"atomization energy"# and #"bond dissociation energy"#?

1 Answer
Mar 6, 2017

Well, #"the atomization energy is the energy associated..........."#

Explanation:

#"the atomization energy is the energy associated with the "#
#"formation of 1 mole of gaseous atoms from 1 mole of gaseous"#
#"element in its standard state under standard conditions......"#

#"and the bond dissociation energy is the energy associated with"# #"the CLEAVAGE of 1 mole of gaseous bonds from 1 mole of"#
#"gaseous molecules to form 2 gaseous radicals........."#

So there are our definitions; let's see if we can represent each process by an equation, using a bimolecular species, #X_2#, as our exemplar:

#"ATOMIZATION:"#

#1/2X_2(g) + "E"_1rarr dotX(g)#

#DeltaE_1="something"#

#"DISSOCIATION:"#

#X-X(g) + "E"_2rarr 2dotX(g)#

#DeltaE_2="some other thing"#

So given the definition, if we have a homonuclear diatomic, i.e. dihydrogen, dihalogen, etc, then #DeltaE_2=2xxDeltaE_1#. That is the #"energy of atomization"# is HALF the #"bond dissociation energy"# for gaseous homonuclear diatomic molecules.