Lattice energy of  $NaCl\left(s\right)$  is $-790kJmo{l}^{-1}$  and enthalpy of hydration is  $-785kJmo{l}^{-1}$ . Calculate enthalpy of  solution of  ${\mathrm{NaCl}}_{\left(s\right)}$   in  $(kJ/mol)$ .