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Description
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White or colourless crystals or a white crystalline powder
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Identifications
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-
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Identification 'A'
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Gives the reactions of chlorides
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Identification 'B'
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Gives the reactions of sodium salts
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Appearance of solution
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Solution A should be clear and colourless
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Acidity or alkalinity
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Not more than 0.5 ml of 0.01 M hydrochloric acid or of 0.01 M sodium hydroxide is required to change the colour of the solution
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Arsenic
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NMT 1 ppm
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Barium
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No turbidity is produced within 2 hours
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Bromides
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NMT 100 ppm
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Calcium & magnesium
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NMT 50 ppm
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Ferrous ion (Fe2+)
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No blue colour should be produced within 10 minutes
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Heavy metals
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NMT 5 ppm
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Iodides
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The substance shows no blue colour after 5 minutes
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Iron
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NMT 20 ppm
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Sulphates
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NMT 300 ppm
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Sulphates
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NMT 1.0%
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Assay (on dried basis)
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99.0 – 100.5%
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Potassium (K)
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NMT 0.1 %
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Aluminium
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NMT 0.2 ppm (The fluorescence of the test solution is not greater than that of the standard solution)
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