SOLUBILITY RULES
Helpful 4 Confusing 2
All common compounds of NH₄⁺ and the Group 1 elements are soluble
NO₃⁻, ClO₃⁻, ClO₄⁻, C₂H₃O₂.⁻ — all common nitrates, chlorates, perchlorates, and acetates are soluble.
F⁻, Cl⁻, Br⁻, I⁻ — all halides are soluble EXCEPT those of Ag⁺, Hg₂²⁺, Pb²⁺ and the fluorides of Mg²⁺, Ca²⁺, Sr²⁺, and Ba²⁺.
SO₄²⁻ — most sulfates are soluble EXCEPT those of Sr²⁺, Ba²⁺, Ca²⁺, Pb²⁺, Hg₂²⁺, and Hg²⁺.
CO₃²⁻, C₂O₄²⁻, OH⁻, O²⁻, SO₃²⁻, PO₄³⁻, CrO₄²⁻, S²⁻ — all carbonates, oxalates, hydroxides, oxides, phosphates, chromates, and sulfides are insoluble.
EXAMPLES
Classify these compounds as soluble or insoluble in water:
tin(II) sulfate — soluble (Rule 4)
lead(II) chromate — insoluble (Rule 5)
ammonium sulfide — soluble (Rule 1)
strontium chlorate — soluble (Rule 2)
silver bromide — insoluble (Rule 3)
sodium phosphate — soluble (Rule 1)
copper(I) carbonate — insoluble (Rule 5)
barium sulfate — insoluble (Rule 4)