Aqueous Solubility Rules

Table 1: General aqueous solubility rules of inorganic compounds

Ions	Exceptions
Soluble
Alkali metals Li⁺, Na⁺, K⁺, etc.	none
Ammonium Ions NH₄⁺	none
Nitrates, acetates, chlorates, and perchlorate NO₃^–, C₂H₃O₂^–, ClO₃^–, ClO₄^–	none
Halides Cl^–, Br^–, and I^–	Ag⁺, Hg₂²⁺, Pb²⁺
Fluorides F^–	Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺
Sulfates SO₄^2–	Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺, Ag⁺, Hg₂²⁺
Insoluble
Carbonates, phosphates, oxalates, chromates, and silicates CO₃^2–, C₂O₄^2–, CrO₄^2–, PO₄^3–, SiO₄^2–	Na⁺, K⁺, NH₄⁺
Sulfides S^2–	Na⁺, K⁺, NH₄⁺, Ba²⁺
Hydroxides with metals OH^–	alkali metals, Ba²⁺ (moderately soluble), Ca²⁺ (very slightly soluble), and Sr²⁺ (slightly soluble)
Oxides with Metals O^2–	alkali metals and Ba²⁺ (slightly soluble)