Should ALL ionic compounds be soluble in water?
Ionic compounds are non-molecular species, which consist of a an infinite array of positive and negative ions held together in an infinite array stabilized by strong electrostatic forces. Water is an exceptionally good solvent for SOME ionic species, no doubt due to the polarity of water, and its ability to stabilize both positive and negative ions, which could lead to a representation of
With the exception of sulfates (the which tend to be uniformly solube in water with a few exceptions), the salts of doubly or trebly charged anions tend to be insoluble, i.e. carbonates, biphosphates, oxides. And clearly, here, the ionic charge is strengthened by the charge on the ions.
Solvents such as ethanol, and methanol, and methylene chloride, offer poor solubility to ionic salts, due to their inability to separate the charges.