Solubility Rules

Li+ soluble with

all anions except F and PO4

Na+ soluble with

all anions

K+ soluble with

all anions

Mg2+ 

Soluble with all anions except F, OH, CO3 and PO4

Ca2+soluble with

Cl, Br, I, NO3, CrO4 and CH3CO2

Ca2+ insoluble with

F, CO3, and PO4

Ca2+ slightly soluble with 

OH, S2-, and SO42-

Ba2+ soluble with

Cl, Br, I, OH, NO3, CH3CO2

NO3

Soluble with all cations

Ba2+ insoluble with 

SO4, CO3, CrO4 and PO4

Ba2+ slighly soluble with

F, S

Al3+ insoluble with

OH, PO4

Al3+ slightly soluble with

CH3CO2

Al3+ soluble with 

F, Cl, Br, I, SO4, PO4

Fe3+ soluble with 

Cl, Br, SO4, NO3, CH3CO2

Fe3+ slightly soluble with

F

Fe3+ insoluble with 

OH, S, CrO4, PO4

Cu2+ soluble with

F, Cl, Br, SO4, NO3, CH3CO2

Cu2+ slightly soluble with

CO3

Cu2+ insoluble with

OH, S, PO4, CrO4

Ag+ soluble with

F, NO3, CH3CO2

Ag+ insoluble with

Cl, Br, I, S, CO3, PO4, CrO4

Ag+ slightly soluble with 

SO4

Zn2+ soluble with

F, Cl, Br, I, SO4, NO3, CH3CO2

Zn2+ insoluble with

OH, S, CO3, PO4, CrO4

Pb2+ soluble with 

Cl, NO3, CH3CO2

Pb2+ slightly soluble with

Br

Pb2+ insoluble with

F, I, OH, S, SO4, CO3, PO4, CrO4

Group 1 cations and NH4

Always soluble

Acetate (C2H3O2)

Always soluble except slightly soluble with calcium

Cl, Br, I

Soluble except with Ag+, Pb2+ and Hg2+ because polar covalent bonds instead ionic, two big ions

SO4

Soluble except with Ba2+, Pb2+, Sr2+, and Ca2+ because high lattice energy due to charges and big ions

OH

Insoluble except for Group 1 and Ba2+ because forms covalent bonds with transiiton metals in solid, high lattice energy with small group 2 cations

S2-

Insoluble with Group 1, Group 2 and NH4 because of high lattice energy due to high charges

CO3

Insoluble except with Group 1 and NH4 because of high lattice energy due to high charges

PO4

Insoluble except with Group 1 and NH4 because of high lattice energy due to high charges

F insoluble with

Li, all cations with charge +2 and higher because of high lattice energy due to small ion size 

Cu+ halides

Insoluble due to high electronegativity and covalency

4th period M+2 halides

Form stable complexes in H2O so are soluble

Ionic colids containing +2/+2 charged fourth row transitions metals or Al+43

Soluble if counterion is -1 except F- and OH-

Ionic solids exception

Lattice energy is too strong to break because the ions are very small

Cl, Br, I Soluble with group 2 metals

because low covalency and group 2 metals have high solvation energy

SO4 Soluble with Mg2+ and +2 period 4 transition metals

because size mismatch leads to very negative solvation energy

OH soluble with Ba2+

Because Ba2+ is a large ion leading to weak attration

High ionic charges

Expect high lattice energy may limit low solubility

High ionic charges but size mismatch

Water wedges in leading to solubility