What is "h2feo4"

Ferric \Fer"ric\, a. [L. ferrum iron: cf. F. ferrique. See Ferrous.] Pertaining to, derived from, or containing iron. Specifically (Chem.), denoting those compounds in which iron has a higher valence than in the ferrous compounds; as, ferric oxide; ferric acid.

Ferric acid (Chem.), an acid, H2FeO4, which is not known in the free state, but forms definite salts, analogous to the chromates and sulphates.

Ferric oxide (Chem.), sesquioxide of iron, Fe2O3; hematite. See Hematite.