precipitation reactions (solubility rules)

rule 1

all salts w/Na⁺, K⁺, NH₄⁺, NO₃^-, ClO₃^-, ClO₄^-, CH₃CO₂^- are soluble

rule 2 (w/o exceptions)

almost all salts of Cr^-, Br^-, I^- are soluble

rule 2 exceptions

Ag⁺, Hg₂²⁺, Pb²⁺ - insoluble w/group 2

rule 3

almost all salts of F^- are soluble

rule 3 exceptions

Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺ insoluble w/group 3

rule 4

almost all salts of SO₄^- are soluble

rule 4 exceptions

Ag⁺, Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺ insoluble w/group 4

rule 5

most salts of CO₃²⁺, PO₄^3-, C₂O₄^2-, CrO₄^2-, S^2- insoluble

exceptions to rule 5

NH₄⁺, group 1 cations, BaS, soluble w/group 5

rule 6

most salts of metal hydroxides and oxides are soluble

exceptions to rule 6

group 1 hydroxides, Ba(OH)₂, Sr(OH)₂

nitrate

NO₃^-

chlorate

ClO₃^-

perchlorate

ClO₄^-

acetate

CH₃CO₂^-

ammonium

NH₄⁺

carbonate

CO₃²⁺

phosphate

PO₄^3-

oxalate

C₂O₄^2-

chromate

CrO₄^2-

hydroxide

OH^-

oxide

O

barium hydroxide

Ba(OH)₂

strontium hydroxide

Sr(OH)₂