Difference in lattice energy and hydration energy of \(\mathrm{LiCl}\) is higher i.e. \(-31 \mathrm{kJmol}^1[-876-(-845)]\) than that of LiF i.e. \(-14 \mathrm{~kJ} \mathrm{~mol}^{-1}[-1019-(-1005)]\) and hence \(\mathrm{LiF}\) is sparingly soluble in water while \(\mathrm{LiCl}\) in soluble. In nut shell, we can say that \(\mathrm{LiF}\) is almost insoluble in water because of much higher lattice energy \(\left(-1005 \mathrm{~kJ} \mathrm{~mol}^{-1}\right)\) than that of \(\mathrm{LiCl}\left(-845 \mathrm{~kJ} \mathrm{~mol}^{-1}\right)\). Furthermore, \(\mathrm{Li}^{+}\)ion can polarize bigger \(\mathrm{Cl}^{-}\)ion more easily than the smaller \(\mathrm{F}^{-}\)ion. As a result, according to Fajan rules, \(\mathrm{LiCl}\) has more covalent character than \(\mathrm{LiF}\) and hence is soluble in organic solvents like acetone