Solubility Rules

Soluble:

• All alkali cations and ammonium (NH4+)

• All nitrates (NO3-), acetates (C2H3O2-), chlorates (ClO3-), and perchlorates (ClO4-)

• All* chloride (Cl-), bromide (Br-), and iodide (I-) anions

• Sulfate (SO4-2)**

  * (except with Ag+, Hg2+, and Pb2+)

  ** (except with Ag+, Hg2+, Pb2+, and heavy alkalines Ca, Sr, Ba)

Insoluble:

• All* carbonates (CO3-2), oxides (O-2), silicates (SiO3-2), chromates (CrO4-2), sulfites (SO3-2), and phosphates (PO4-3)

• Hydroxides (OH-)**

• Sulfides (S-2)***

• Fluoride (F-)*

  * (except with Ag+, Hg2+, and Pb2+)

  ** (except with alkali and heavy alkalines Ca2+, Sr2+, Ba2+)

  *** (except alkali and alkaline metals)