Iron(II) oxalate

Iron(II) oxalate
Names
	IUPAC name Iron(II) oxalate
	Systematic IUPAC name Iron, diaqua(ethanedioato(2-)-O,O')- (dihydrate)
	Other names Iron oxalate; Ferrous oxalate;
Identifiers
CAS Number	(anhydrous): 516-03-0 ; (dihydrate): 6047-25-2 ;
3D model (JSmol)	(anhydrous): Interactive image; (dihydrate): Interactive image;
ChemSpider	(anhydrous): 10144; (dihydrate): 450862;
ECHA InfoCard	100.007.472
EC Number	(anhydrous): 208-217-4; (dihydrate): 611-981-5;
PubChem CID	(anhydrous): 10589; (dihydrate): 516788;
UNII	(anhydrous): DZP4YV3ICV ; (dihydrate): Z6X3YBU50D ;
CompTox Dashboard (EPA)	DTXSID4060159 ; (dihydrate): DTXSID90975879;
	InChI InChI=1S/3C2H2O4.2Fe/c33-1(4)2(5)6;;/h3(H,3,4)(H,5,6);;/q;;;2+3/p-6 Key: VEPSWGHMGZQCIN-UHFFFAOYSA-H ; (dihydrate): InChI=1S/C2H2O4.Fe.2H2O/c3-1(4)2(5)6;;;/h(H,3,4)(H,5,6);;21H2/q;+2;;/p-2 Key: NPLZZSLZTJVZSX-UHFFFAOYSA-L;
	SMILES (anhydrous): [Fe+2].O=C([O-])-C([O-])=O; (dihydrate): C(=O)(C(=O)[O-])[O-].O.O.[Fe+2];
Properties
Chemical formula	FeC2O4 (anhydrous); FeC2O4·2H2O (dihydrate);
Molar mass	143.86 g⋅mol−1 (anhydrous); 179.89 g⋅mol−1 (dihydrate);
Appearance	yellow powder
Odor	odorless
Density	2.28 g/cm3
Melting point	~120 °C (248 °F; 393 K) (dihydrate, decomposes to anhydrous); 190 °C (374 °F; 463 K) (anhydrous, decomposes);
Solubility in water	0.097 g/100g (dihydrate)
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302+H312
Precautionary statements	P264, P270, P280, P301+P312+P330, P302+P352+P312, P363, P501
NFPA 704 (fire diamond)	2 1 1
Threshold limit value (TLV)	1 mg/m3 (TWA)
	NIOSH (US health exposure limits):
PEL (Permissible)	1 mg/m3 (TWA, vacated)
REL (Recommended)	1 mg/m3 (TWA)
	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

Ferrous oxalate (iron(II) oxalate) refers to the inorganic compound with the formula FeC₂O₄ (anhydrous) or FeC₂O₄·2H₂O (dihydrate). These are yellow compounds. Characteristic of metal oxalate complexes, these compounds tend to be polymeric, hence their low solubility in water. The dihydrate is hygroscopic.