Given the balanced equation representing a reaction: #2NaCl -> 2Na + Cl_2#. What must happen to energy in the reaction to break the bonds in NaCl?

1 Answer
Mar 16, 2017


Well, a great deal of energy must be expended to break the strong ionic bond........


Certainly we could measure the enthalpy change for the following reaction:

#Na(s) + 1/2Cl_2(g) rarr NaCl(s) + Delta#, and in the reverse reaction, of course, the same amount of energy must be expended as was released when the ionic bond was formed:

#NaCl(s) + Delta rarr Na(s) + 1/2Cl_2(g)#

This goes back to the old principle we learn when we begin chemistry:

#"the breaking of bonds REQUIRES energy; the making"#
#"of bonds RELEASES energy."#

Are these ideas consistent with the principle of conservation of energy?