Molecular formula: FeSO4.7H2O (seven water) FeSO4.nH2O (dry product)
Molecular formula: Heptahydrate: FeSO4·7H2O; Dry product: FeSO4·nH2O
Molecular weight: Heptahydrate: 278.01;
CAS: Heptahydrate: 7782-63-0; Dry product: 7720-78-7
Heptahydrate: blue-green crystals or granules. Odorless, slightly salty, astringent. It will weather in dry air and easily oxidize to brown-yellow basic ferric sulfate in humid air. It is easily soluble in water, insoluble in ethanol.
Nutritional supplements (iron fortifiers), fruit and vegetable colorants.
| Ferrous sulfate content % | 99.87 | |
| Lead（Pb）mg/kg | ≤2 | |
| Mercury（Hg）mg/kg | ≤1 | |
| Arsenic（As）mg/kg | ≤3 | |
