Chemistry · THERMODYNAMICS

Why is it impossible to determine the lattice enthalpy of an ionic crystal like \( \text{NaCl}(s) \) directly by experiment?

1. A
   Because an isolated ionic solid cannot be vaporized directly into separated gaseous ions without supplying high thermal energy that triggers non-ionic decomposition.
2. B
   Because standard states of sodium and chlorine are not gases under normal conditions.
3. C
   Because the gaseous ions immediately condense back into solid before thermal changes can be measured.
4. D
   Because the process involves non-stoichiometric electronic transitions.