Solubility Product Constants for Some Inorganic Compounds at 25oC*
Substance
Ksp
Aluminum compounds
AlAsO4
1.6 x 10-16
Al(OH)3
1.9 x 10-33
AlPO4
1.3 x 10-20
Barium compounds
Ba3(AsO4)2
1.1 x 10-13
BaCO3
8.1 x 10-9
BaC2O4·2H2O**
1.1 x 10-7
BaCrO4
2.0 x 10-10
BaF2
1.7 x 10-6
Ba(OH)2·8H2O**
5.0 x 10-3
Ba3(PO4)2
1.3 x 10-29
BaSeO4
2.8 x 10-11
BaSO3
8.0 x 10-7
BaSO4
1.1 x 10-10
Bismuth compounds
BiOCl
7.0 x 10-9
BiO(OH)
1.0 x 10-12
Bi(OH)3
3.2 x 10-40
BiI3
8.1 x 10-19
BiPO4
1.3 x 10-23
Cadmium compounds
Cd3(AsO4)2
2.2 x 10-32
CdCO3
2.5 x 10-14
Cd(CN)2
1.0 x 10-8
Cd2[Fe(CN)6]
3.2 x 10-17
Cd(OH)2
1.2 x 10-14
Calcium compounds
Ca3(AsO4)2
6.8 x 10-19
CaCO3
3.8 x 10-9
CaCrO4
7.1 x 10-4
CaC2O4·H2O**
2.3 x 10-9
CaF2
3.9 x 10-11
Ca(OH)2
7.9 x 10-6
CaHPO4
2.7 x 10-7
Ca(H2PO4)2
1.0 x 10-3
Ca3(PO4)2
1.0 x 10-25
CaSO3·2H2O**
1.3 x 10-8
CaSO4·2H2O**
2.4 x 10-5
Chromium compounds
CrAsO4
7.8 x 10-21
Cr(OH)3
6.7 x 10-31
CrPO4
2.4 x 10-23
Cobalt compounds
Co3(AsO4)2
7.6 x 10-29
CoCO3
8.0 x 10-13
Co(OH)2
2.5 x 10-16
Co(OH)3
4.0 x 10-45
Copper compounds
CuBr
5.3 x 10-9
CuCl
1.9 x 10-7
CuCN
3.2 x 10-20
Cu2O(Cu+ + OH-)***
1.0 x 10-14
CuI
5.1 x 10-12
CuSCN
1.6 x 10-11
Cu3(AsO4)2
7.6 x 10-36
CuCO3
2.5 x 10-10
Cu2[Fe(CN)6]
1.3 x 10-16
Cu(OH)2
1.6 x 10-19
Gold compounds
AuBr
5.0 x 10-17
AuCl
2.0 x 10-13
AuI
1.6 x 10-23
AuBr3
4.0 x 10-36
AuCl3
3.2 x 10-25
Au(OH)3
1.0 x 10-53
AuI3
1.0 x 10-46
Iron compounds
FeCO3
3.5 x 10-11
Fe(OH)2
7.9 x 10-15
FeS
4.9 x 10-18
Fe4[Fe(CN)6]3
3.0 x 10-41
Fe(OH)3
6.3 x 10-38
Lead compounds
Pb3(AsO4)2
4.1 x 10-36
PbBr2
6.3 x 10-6
PbCO3
1.5 x 10-13
PbCl2
1.7 x 10-5
PbCrO4
1.8 x 10-14
PbF2
3.7 x 10-8
Pb(OH)2
2.8 x 10-16
PbI2
8.7 x 10-9
Pb3(PO4)2
3.0 x 10-44
PbSeO4
1.5 x 10-7
PbSO4
1.8 x 10-8
Magnesium compounds
Mg3(AsO4)2
2.1 x 10-20
MgCO3·3H2O**
4.0 x 10-5
MgC2O4
8.6 x 10-5
MgF2
6.4 x 10-9
MgNH4PO4
2.5 x 10-12
Manganese compounds
Mn3(AsO4)2
1.9 x 10-11
MnCO3
1.8 x 10-11
Mn(OH)2
4.6 x 10-14
Mn(OH)3
~1 x 10-36
Mercury compounds
Hg2Br2
1.3 x 10-22
Hg2CO3
8.9 x 10-17
Hg2Cl2
1.1 x 10-18
Hg2CrO4
5.0 x 10-9
Hg2I2
4.5 x 10-29
Hg2O·H2O(Hg22+ + 2OH-)**,***
1.6 x 10-23
Hg2SO4
6.8 x 10-7
Hg(CN)2
3.0 x 10-23
Hg(OH)2
2.5 x 10-26
HgI2
4.0 x 10-29
Nickel compounds
Ni3(AsO4)2
1.9 x 10-26
NiCO3
6.6 x 10-9
Ni(CN)2
3.0 x 10-23
Ni(OH)2
2.8 x 10-16
Silver compounds
Ag3AsO4
1.1 x 10-20
AgBr
3.3 x 10-13
Ag2CO3
8.1 x 10-12
AgCl
1.8 x 10-10
Ag2CrO4
9.0 x 10-12
AgCN
1.2 x 10-16
Ag4[Fe(CN)6]
1.6 x 10-41
Ag2O(Ag+ + OH-)***
2.0 x 10-8
AgI
1.5 x 10-16
Ag3PO4
8.9 x 10-17
Ag2SO3
1.5 x 10-14
Ag2SO4
1.7 x 10-5
AgSCN
1.0 x 10-12
Strontium compounds
Sr3(AsO4)2
1.3 x 10-18
SrCO3
9.4 x 10-10
SrC2O4·2H2O**
5.6 x 10-8
SrCrO4
3.6 x 10-5
Sr(OH)2·8H2O**
3.2 x 10-4
Sr3(PO4)2
1.0 x 10-31
SrSO3
4.0 x 10-8
SrSO4
2.8 x 10-7
Tin compounds
Sn(OH)2
2.0 x 10-26
SnI2
1.0 x 10-4
Sn(OH)4
1.0 x 10-57
Zinc compounds
Zn3(AsO4)2
1.1 x 10-27
ZnCO3
1.5 x 10-11
Zn(CN)2
8.0 x 10-12
Zn3[Fe(CN)6]
4.1 x 10-16
Zn(OH)2
4.5 x 10-17
Zn3(PO4)2
9.1 x 10-33
* No metallic sulfides are listed in this table because sulfide ion is such a strong base that the usual solubility product equilibrium equation does not apply. See Myers, R. J., J. Chem. Educ. 1986, 63, 687-690.
** Since [H2O] does not appear in equilibrium constants for equilibria in aqueous solution in general, it does not appear in the Ksp expressions for hydrated solids.
*** Very small amounts of oxides dissolve in water to give the ions indicated in parentheses. Solid hydroxides are unstable and decompose to oxides as rapidly as they are formed.