Solubility Rules

NO3-

all nitrates are soluble

C2H3O2-

all acetates are soluble

Cl-

soluble except AgCl, Hg2Cl2, and PbCl2

Br-

soluble except AgBr, Hg2Br2, and PbBr2

I-

soluble except Ag, Hg and Pb

IO3-

all iodates soluble except Sr(IO3)2, Ca(IO3)2, Ba(IO3)2, Pb(IO3)2, Hg2(IO3)2, and AgIO3

SO4-2

all sulfates soluble except CaSO4, SrSO4, BaSO4, PbSO4, and Hg2SO4

S-2

all sulfides insoluble except those of 1A elements Ba(OH)2, Sr(OH)2, Ca(OH)2, (NH4)2S

CO3-2

carbonates insoluble except 1A elements (NH4)2CO3

PO4-3

phosphates insoluble except 1A elements and (NH4)3PO4

OH-

hydroxides insoluble except 1A elements and NH4, Ba(OH)2, Sr(OH)2, and Ca(OH)2

NH4+

always soluble

halides

soluble (Cl- Br- I-) exceptions: Ag, Hg2, and Pb

ClO4-

always soluble