FeC2O4

FeC2O4, also known as iron(II) oxalate, is an inorganic compound. It is a salt formed between iron in the +2 oxidation state and the oxalate anion. In its anhydrous form, FeC2O4 is typically a pale yellow solid. It can also exist as hydrates, such as the dihydrate, FeC2O4·2H2O, which has a lighter color.

Iron(II) oxalate is sparingly soluble in water. It decomposes upon heating, typically yielding iron(II) oxide and carbon oxides. This decomposition reaction is often used in analytical chemistry or for the preparation of iron oxides.

FeC2O4 can be synthesized by reacting iron(II) salts, such as iron(II) sulfate or iron(II) chloride, with a soluble oxalate salt, like sodium oxalate, in an aqueous solution. The precipitate of iron(II) oxalate can then be filtered and dried.

Historically, iron(II) oxalate has found some minor applications, for instance, in photography as a toning agent or as a component in certain pigments. However, its use in these areas has largely been superseded by other compounds. It is also encountered in research settings for its chemical properties and potential applications in materials science.