The salts are more ionic, more soluble they are in water since H2O is a polar solvent. LiF and CsI are much less polar than LiI and CSF since the latters are more ionic bonded. Solution The salts are more ionic, more soluble they are in water since H2O is a polar solvent. LiF and CsI are much less polar than LiI and CSF since the latters are more ionic bonded..