Iron(II) hydroxide

Iron(II) hydroxide
Names
	IUPAC name Iron(II) hydroxide
	Other names Ferrous hydroxide, green rust
Identifiers
CAS Number	18624-44-7 ;
3D model (JSmol)	Interactive image;
ChemSpider	8305416 ;
ECHA InfoCard	100.038.581
PubChem CID	10129897;
UNII	7JIM5W32UU ;
CompTox Dashboard (EPA)	DTXSID8066393 ;
	InChI InChI=1S/Fe.2H2O/h;21H2/q+2;;/p-2 Key: NCNCGGDMXMBVIA-UHFFFAOYSA-L ; InChI=1/Fe.2H2O/h;21H2/q+2;;/p-2 Key: NCNCGGDMXMBVIA-NUQVWONBAV;
	SMILES O[Fe]O;
Properties
Chemical formula	Fe(OH)2
Molar mass	89.86 g/mol
Appearance	green solid
Density	3.4 g/cm3
Solubility in water	0.000052 g/100 g water (20 °C, pH 7)
Solubility product (Ksp)	8.0 x 10−16
Acidity (pKa)	17
Hazards
Flash point	Non-flammable
Related compounds
Related compounds	Iron(II) oxide; Iron(III) hydroxide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Iron (II) hydroxide or ferrous hydroxide is an inorganic compound with the formula Fe(OH)₂. It is produced when iron (II) salts, from a compound such as iron(II) sulfate, are treated with hydroxide ions. Iron(II) hydroxide is a white solid, but even traces of oxygen impart a greenish tinge. The air-oxidised solid is sometimes known as "green rust".