Ferrous Sulphate
H A E M A t I N I C s Ferrous Sulphate (FeSO₄.7H₂O) molecular weight = 278 Not less than 98% not more than 103.3 N PREPARATIONS It is obtained by dissolving iron in excess of dil. H₂SO ₄ After the effervescence stops ---> liquid is filtered, concentrated and cooled. The green crystals are formed In all this operations undue exposure to air is prevented, because ferrous sulphate is oxidized readily on exposure to moist air and the crystal gets coated with brownish yellow ferric sulphate. Fe + H₂SO ₄ ------> FeSO₄ + H₂ ↑ PROPERTIES Occurs in green crystals or crystalline powders, Astringent taste, Effloresces in dry air, In air, oxidised to ferric salt of brownish yellow color, Soluble in water, Insoluble in alcohol, When heated, decomposes to yield Ferric Oxide, Sulphur dioxide, and sulphuric acid. 2( FeSO₄.7H₂O ) + Heat -------> Fe₂O₃ + SO₂ + H₂SO₄ + 13 H₂O Ferrous sulphate reduces the salts of silver and gold to their corresponding metals. with some alkali sulphates,