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?

Mar 16, 2017

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

Explanation:

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

$N a \left(s\right) + \frac{1}{2} C {l}_{2} \left(g\right) \rightarrow N a C l \left(s\right) + \Delta$, and in the reverse reaction, of course, the same amount of energy must be expended as was released when the ionic bond was formed:

$N a C l \left(s\right) + \Delta \rightarrow N a \left(s\right) + \frac{1}{2} C {l}_{2} \left(g\right)$

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

$\text{the breaking of bonds REQUIRES energy; the making}$
$\text{of bonds RELEASES energy.}$

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