Are all ionic substances soluble in water?

Question

Henry Antrim · Accepted Answer

Absolutely not. A great many ionic species are INSOLUBLE in water.

Ionic compounds are non-molecular. They consist of a rigid array of positive and negative ions, whose attractive electrostatic interaction persists throughout the ionic lattice. A measure of this ionic interaction can be measured (both experimentally and theoretically) by the lattice enthalpy. In earlier studies of chemistry we learn that all carbonates, phosphates, and oxides are insoluble in water (I think you know the exceptions). Water is a good solvent for ions inasmuch as it can effectively stabilize the individual cations and anions. Nevertheless, there are a great many ionic species that are insoluble in water, and this is attributable to the strength of the ionic interaction: ions with charges greater than #+-1# all tend to be insoluble; all except for the sulfates, and sulfates are only soluble in aqueous phases. Nitrates, halides, and acetates tend to have considerable water solubility. Of course, network covalent solids are also non-molecular, and the individual particles are bound together by strong covalent bonds. You would have a hard time dissolving graphite or silicon dioxide in water. I am certainly willing to expand on the subject. It depends whether you are in A level or are an undergraduate.

Caleb Adams · Answer

undefined Not all ionic substances are soluble in water. The solubility of an ionic compound depends on the strength of the bonds holding its ions together and the interactions between the ions and water molecules. Generally, compounds with strong ionic bonds or with ions that are highly charged tend to be less soluble in water. Additionally, compounds with large ions or with ions that have a strong affinity for water tend to be more soluble.