Are bond energies (single and multiple bonds) applicable only to gas phase?? For instance, I can use the bond energy data to calculate for enthalpy of reaction for the formation of water:

Question

Are bond energies (single and multiple bonds) applicable only to gas phase?? For instance, I can use the bond energy data to calculate for enthalpy of reaction for the formation of water:

2 H2(g) + O2(g) -> H2O(g)
But I can't directly use it to calculate for neutralization of acid and base:
HCl(aq) + NaOH(aq) -> NaCl(aq) + H2O(l)

help please.

Answer 1

Are bond energies (single and multiple bonds) applicable only to gas phase?? For instance, I can use the bond energy data to calculate for enthalpy of reaction for the formation of water:

Yes. Using bond energy to calculate dHrxn etc are good only for gases(and covalent bonds).