Solubility Rules

The following solubility rules were taken from "Laboratory Experiments in General Chemistry", Alan Pribula, Scientific American Books,1989.

1. All salts of Na+, K+, and NH4+ are soluble.

2. All salts of NO3-, ClO3-, and C2H3O2- are soluble.
(AgC2H3O3 is partially soluble.)

3. All salts of halides and SCN- are soluble except those of Ag +, Cu+, Pb2+, and Hg22+. (HgI2 is also insoluble. PbCl2 is soluble in hot water.)

4. All salts of SO42- are soluble except for BaSO4 , PbSO4 , and SrSO4 . (CaSO4 , Ag2SO4 and Hg2SO4 are partially soluble.

5. All salts of CO32-, PO43-,SiO32-, C2O42-, and SO32- are insoluble, except for those of Na+, K+, and NH4+. (MgC2O4 and Cr2(C2O4)3 are also soluble.)

6. All oxides and hydroxides are insoluble except for those of Na+, K+, and Ba2+. (Ca(OH)2 is partially soluble.)

7. All salts of S2- are insoluble except for those of Group IA and IIa elements and of NH4+.