CHEM109 Solubility Rules

Group 1 cations

Soluble, no exceptions

NH₄⁺

Soluble, no exceptions

NO₃^-

Soluble, no exceptions

C₂H₃O₂^-

Soluble, no exceptions

ClO₄^-

Soluble, no exceptions

Cl^-, Br^-, I^-

Soluble, except Cu⁺, Ag⁺, Hg₂²⁺, Pb²⁺

SO₄^2-

Soluble, except Sr²⁺, Ba²⁺, Hg₂²⁺, Pb²⁺

OH^-, O^2-

Insoluble, except Group 1 cations, NH₄⁺, Ba²⁺ (Ca²⁺ and Sr²⁺ are moderately soluble.)

S^2-

Insoluble, except Group 1 cations, NH₄⁺ and Ca²⁺, Sr²⁺, Ba²⁺

CO₃^2-, PO₄^3-

Insoluble, except Group 1 cations and NH₄⁺