![]() | |
![]() | |
Names | |
---|---|
IUPAC name Iron(II) oxalate | |
Other names Iron oxalate Ferrous oxalate | |
Identifiers | |
3D model (JSmol) |
|
ChemSpider | |
ECHA InfoCard | 100.007.472 |
EC Number |
|
PubChem CID | |
UNII |
|
CompTox Dashboard (EPA) |
|
| |
| |
Properties | |
FeC2O4 (anhydrous) FeC2O4 · 2 H2O (dihydrate) | |
Molar mass | 143.86 g/mol (anhydrous) 179.89 g/mol (dihydrate) |
Appearance | yellow powder |
Odor | odorless |
Density | 2.28 g/cm3 |
Melting point | dihydrate: 150–160 °C (302–320 °F; 423–433 K) (decomposes) |
dihydrate: 0.097 g/100ml (25 °C) [1] | |
Hazards | |
GHS labelling: | |
![]() | |
Warning | |
H302, H312 [2] | |
P280 [2] | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Ferrous oxalate (iron(II) oxalate) refers to inorganic compounds with the formula FeC2O4(H2O)x where x is 0 or 2. These are yellow compounds. Characteristic of metal oxalate complexes, these compounds tend to be polymeric, hence their low solubility in water.
Like other iron oxalates, ferrous oxalates feature octahedral Fe centers. The dihydrate FeC2O4(H2O)2 is a coordination polymer, consisting of chains of oxalate-bridged ferrous centers, each with two aquo ligands. [3]
When heated to 120 °C, the dihydrate dehydrates, and the anhydrous ferrous oxalate decomposes near 190 °C. [4] The product of thermal decomposition is a mixture of iron oxides and pyrophoric iron metal, as well as released carbon dioxide, carbon monoxide, and water. [5]
Ferrous oxalates are precursors to iron phosphates, which are of value in batteries. [6]
Anhydrous iron(II) oxalate is unknown among minerals as of 2020. However, the dihydrate is known as humboldtine. [7] [8] A related mineral is stepanovite (Na[Mg(H2O)6][Fe(C2O4)3]·3H2O), an unusual example of a naturally-occurring ferrioxalate. [9] [8]