A13 Solubility Rules

1. A salt is soluble if it contains any of the following ions:

NH_4­⁺, Li⁺, Na⁺, K⁺ or NO₃^-

Examples

LiCl, Na₂SO₄, KBr, Ca(NO₃)₂

2. SO₄^2- (sulphate) salts. Salts with SO₄^2-  are soluble, but not if the positive ion is:

Ba²⁺, Pb²⁺, Hg²⁺, Ca²⁺

Examples

Soluble	Insoluble
MgSO4	BaSO4 PbSO4

3. Other Salts. Other salts containing CO₃^2-, PO₄^3-, S^2- and OH^- are not soluble

Examples

Soluble	Insoluble
Na2CO3 K2S	CaCO3 CuS