iron(ii) sulfate iron(ii) sulfate iron(ii) sulfate iron(ii) sulfate when dissolved in water names iupac name iron(ii) sulfate other names iron(ii) sulphate; ferrous sulfate, green vitriol, iron vitriol, ferrous vitriol, copperas, melanterite, szomolnokite, identifiers cas number anhydrous: 7720-78-7 ymonohydrate: 17375-41-6 ydihydrate: 10028-21-4 yheptahydrate: 7782-63-0 y 3d model (jsmol) anhydrous: interactive image chebi anhydrous: chebi:75832 n chembl anhydrous: chembl1200830 n chemspider anhydrous: 22804 ymonohydrate: 56459 nheptahydrate: 22804 n echa infocard 100.028.867 ec number anhydrous: 231-753-5 pubchem cid anhydrous: 24393monohydrate: 62712heptahydrate: 62662 rtecs number anhydrous: no8500000 (anhydrous)no8510000 (heptahydrate) unii anhydrous: 2idp3x9oud ymonohydrate: rib00980vw ydihydrate: g0z5449449 yheptahydrate: 39r4tan1vt y un number 3077 comptox dashboard (epa) anhydrous: dtxsid0029688 inchi inchi=1s/fe.h2o4s/c;1-5(2,3)4/h;(h2,1,2,3,4)/q+2;/p-2 ykey: bauygsiqeafulo-uhfffaoysa-l yanhydrous: inchi=1/fe.h2o4s/c;1-5(2,3)4/h;(h2,1,2,3,4)/q+2;/p-2key: bauygsiqeafulo-nuqvwonbas smiles anhydrous: s(=o)(=o). properties chemical formula feso4 molar mass 151.91 g/mol (anhydrous) 169.93 g/mol (monohydrate) 241.99 g/mol (pentahydrate) 260.00 g/mol (hexahydrate) 278.02 g/mol (heptahydrate) appearance white crystals (anhydrous)white-yellow crystals (monohydrate)blue-green crystals (heptahydrate) odor odorless density 3.65 g/cm3 (anhydrous)3 g/cm3 (monohydrate)2.15 g/cm3 (pentahydrate)1.934 g/cm3 (hexahydrate)1.895 g/cm3 (heptahydrate) melting point 680 °c (1,256 °f; 953 k) (anhydrous) decomposes300 °c (572 °f; 573 k)(monohydrate) decomposes60–64 °c (140–147 °f; 333–337 k)(heptahydrate) decomposes solubility in water monohydrate:44.69 g/100 ml (77 °c)35.97 g/100 ml (90.1 °c)heptahydrate:15.65 g/100 ml (0 °c)19.986 g/100 ml (10 °c)29.51 g/100 ml (25 °c)39.89 g/100 ml (40.1 °c)51.35 g/100 ml (54 °c) solubility negligible in alcohol solubility in ethylene glycol 6.38 g/100 g (20 °c) vapor pressure 1.95 kpa (heptahydrate) magnetic susceptibility (χ) 1.24×10−2 cm3/mol (anhydrous)1.05×10−2 cm3/mol (monohydrate)1.12×10−2 cm3/mol (heptahydrate)+10200×10−6 cm3/mol refractive index (nd) 1.591 (monohydrate)1.526–1.528 (21 °c, tetrahydrate)1.513–1.515 (pentahydrate)1.468 (hexahydrate)1.471 (heptahydrate) structure crystal structure orthorhombic, op24 (anhydrous)monoclinic, ms36 (monohydrate)monoclinic, mp72 (tetrahydrate)triclinic, ap42 (pentahydrate)monoclinic, ms192 (hexahydrate)monoclinic, mp108 (heptahydrate) space group pnma, no. 62 (anhydrous) c2/c, no. 15 (monohydrate, hexahydrate)p21/n, no. 14 (tetrahydrate)p1, no. 2 (pentahydrate)p21/c, no. 14 (heptahydrate) point group 2/m 2/m 2/m (anhydrous)2/m (monohydrate, tetrahydrate, hexahydrate, heptahydrate)1 (pentahydrate) lattice constant a = 8.704(2) å, b = 6.801(3) å, c = 4.786(8) å (293 k, anhydrous)α = 90°, β = 90°, γ = 90° coordination geometry octahedral (fe2+) thermochemistry heat capacity (c) 100.6 j/mol·k (anhydrous)394.5 j/mol·k (heptahydrate) std molarentropy (s⦵298) 107.5 j/mol·k (anhydrous)409.1 j/mol·k (heptahydrate) std enthalpy offormation (δfh⦵298) −928.4 kj/mol (anhydrous)−3016 kj/mol (heptahydrate) gibbs free energy (δfg⦵) −820.8 kj/mol (anhydrous)−2512 kj/mol (heptahydrate) pharmacology atc code b03aa07 (who) hazards ghs labelling: pictograms signal word warning hazard statements h302, h315, h319 precautionary statements p305+p351+p338 nfpa 704 (fire diamond) 1 0 0 lethal dose or concentration (ld, lc): ld50 (median dose) 237 mg/kg (rat, oral) niosh (us health exposure limits): rel (recommended) twa 1 mg/m3 related compounds other cations cobalt(ii) sulfatecopper(ii) sulfatemanganese(ii) sulfatenickel(ii) sulfate related compounds iron(iii) sulfate except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references