The lattice energy of solid NaCl is 180 kcal/mol. The dissolution of the solid in water in the form of ions is endothermic to the extent of 1 kcal/mol. If the hydration energies of `Na^(+)` and `Cl^(-)` are in the ratio 6 : 5, what is the enthalpy of hydration of `Na^(+)` ion?

Options

A. `85.6`K.Cal/mol
B. `-97.5` K.Cal/mol
C. 82.6 K.Cal/mol
D. `+100` K.Cal/mol

Answer

B