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Appearance
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White crystalline powder
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Assay (as C6H6Na2O7.1½ H2O)
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98.0 - 104.0%
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Solubility
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Freely soluble in water & practically Insoluble in methanol
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Identification: Sodium
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-
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Identification 'A'
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i. No precipitate should be formed upon addition of potassium carbonate solution to sample solution and heat to boiling. ii. A dense white precipitate should be formed.
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Identification 'B'
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i. A voluminous, white crystalline precipitate should be formed. ii. No precipitate should be formed
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Identification: Citrates
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-
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Identification 'A'
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A violet colour should be produced upon addition of excess of concentrated ammonia and it turns to violet-blue.
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Identification 'B'
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No precipitate should be formed with addition of calcium chloride solution. A white precipitate should be produced after boiling of above solution and it should be soluble in 6M acetic acid.
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Acidity
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pH of 3% w/v solution in water is between 4.9 to 5.2
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Arsenic
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Maximum 2 ppm
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Chloride (Cl)
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Maximum 330 ppm
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Oxalate (as anhydrous oxalic acid)
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Maximum 150 ppm
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Sulphate (SO4)
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Maximum 0.12%
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Readily carbonisable substance
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Not more than a pale brown colour should be produced
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