Borax BP Ph Eur Grade

Borax BP Ph Eur Grade Borax BP; Sodium Borate; Sodium Tetraborate Na2B4O7,10H2O -- 381.4 -- CAS 1303-96-4 DEFINITION Borax contains not less than 99.0 per cent and not more than the equivalent of 103.0  per cent of disodium tetraborate decahydrate. CHARACTERS A white, crystalline powder, colourless crystals or crystalline masses, efflorescent, soluble in water, very soluble in boiling water, freely soluble in glycerol. IDENTIFICATION A. To 1 ml of solution S (see Tests) add 0.1 ml of sulphuric acid and 5 ml of methanol \ and ignite. The flame has a green border. B. To 5 ml of solution S add 0.1 ml of phenolphthalein solution. The solution is red. On the addition of 5 ml of glycerol (85 per cent) the colour disappears. C. Solution S gives the reactions of sodium. TESTS Solution S Dissolve 4.0 g in carbon dioxide-free water prepared from distilled water and  dilute to 100 ml with the same solvent. Appearance of solutionSolution S is clear and colourless. pHThe pH of solution S is 9.0 to 9.6. Sulphates 15 ml of solution S complies with the limit test for sulphates (50 ppm). Ammonium 6 ml of solution S diluted to 14 ml with water complies with the limit test for  ammonium (10 ppm). Arsenic 5 ml of solution S complies with limit test A for arsenic (5 ppm). Calcium 15 ml of solution S complies with the limit test for calcium (100 ppm). Heavy metals 12 ml of solution S complies with limit test A for heavy metals (25 ppm).