Ionic Compounds in Water - Solubility Guidelines
Guidelines or solubility rules to predict whether or not a given ionic compound is soluble in water at room temperature.
See also Solutions, molarity and dilution and Solubility product constants
| Usually Soluble | Exceptions | |
|---|---|---|
| Acetates | CH3 COO- | Moderately soluble: CH3 COOAg |
| Ammonium | NH4 + | |
| Chlorates | ClO3- | |
| Perchlorates | ClO4 - | |
| Group 1 cations | Li+ | |
| Na+ | ||
| K+ | ||
| Rb+ | ||
| Cs+ | ||
| Halides | F- | Insoluble: MgF2, CaF2, SrF2, BaF2, PbF2 |
| Cl- | Insoluble: AgCl, Hg2Cl2, PbCl2, | |
| Br- | Insoluble: AgBr, Hg2Br2, PbBr2, | |
| I- | Insoluble: AgI, Hg2I2, PbI2, | |
| Nitrates | NO3- | |
| Nitrites | NO2 - | Moderately soluble: AgNO2 |
| Sulfates | SO4 2- |
Moderate soluble: CaSO4 , SrSO4 , Ag2SO4 Insoluble: BaSO4 , PbSO4 , HgSO4 |
| Usually Insoluble | Exceptions | |
|---|---|---|
| Carbonates | CO32- | Soluble: (NH4 )2CO3, Na2CO3, K2CO3 |
| Hydroxides | OH- |
Soluble: LiOH, NaOH, KOH, Ba(OH)2 Moderately soluble: Ca(OH)2, Sr(OH)2 |
| Phosphates | PO4 3- | Soluble: (NH4 )3 PO4 , Na3 PO4 , K3 PO4 |
| Sulfides | S2- | Soluble: (NH4 )2S, Na2S, K2S, MgS, CaS |
