Ferrous oxalate, also known as ferrous oxalate, is an organic compound with the molecular formula of FeC2O4 and molecular weight of 143.86. Stable under normal temperature and pressure, light yellow crystalline powder, slightly irritating. Ferrous oxalate is decomposed into ferrous oxide, carbon monoxide and carbon dioxide by heating, which are used as photographic developer and pharmaceutical industry. Stable, light yellow crystalline powder under normal temperature and pressure. Its hydrate ferrous oxalate dihydrate loses crystalline water at 142 ℃ under vacuum and can be dissolved in cold salt solution. It is insoluble in water and can be slowly dissolved in cold hydrochloric acid.