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Description
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Bluish green crystals or light green, crystalline powder. Efflorescent in air. On exposure to moist air, the crystals rapidly oxidise and becomes brown
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Solubility
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Very soluble in boiling water; freely soluble in water; practically insoluble in ethanol (95%)
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Identification
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It gives the reaction (A) ferrous salts and the reactions of sulphates
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Appearance of solution
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Solution should not more opalescent than opalescent standard OS2
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pH
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3.0 – 4.0
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Arsenic
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NMT 2 ppm
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Copper
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NMT 50 ppm
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Lead
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NMT 50 ppm
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Zinc
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NMT 500 ppm
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Manganese
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NMT 0.1 %
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Ferric ion (Fe+3)
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NMT 0.5%
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Chlorides
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NMT 250 ppm
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Assay (as FeSO4,7H2O)
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98.0-105.0%
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