| Ferric Molybdate, Fe2(MoO4)3.42H2O, is obtained as a yellowish- brown precipitate when an aqueous solution of normal sodium molybdate is treated with ferric chloride. If the di- or para-molybdate is so treated, a yellow precipitate, of composition Fe2O3.5MoO3.aq., separates; with the tetramolybdate a pale yellow precipitate, of composition Fe2O3.10MoO3.110H2O, is obtained on evaporation. Complex salts, of the type 3R•2O.Fe2O3.12MoO3.20H2O (R• = NH4, K), similar to those of aluminium, chromium, and cobalt, have been described. |