Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in acetone ?

Explanation

LiF is almost insoluble in water due to its higher lattice energy `(-1005 kJ mol^(-1))` as compared to that of LiCl `(-845 kJ mol^(-1))` which is soluble in water. Moreover, the degree of polarisation is more in LiCl than in LiF due to larger size of `Cl^(-)` ions as compared to `F^(-)` ion. Due to higher degree of polarisation, LiCl has more covalent character and is soluble in acetone (an organic solvent) also.