Glacial Acetic Acid

Glacial Acetic Acid BP Grade
Ph Eur -- C2H4O2 -- 60.1 -- 64-19-7
DEFINITION
Content:  99.0 per cent m/m to 100.5 per cent m/m.
CHARACTERS
Appearance: Crystalline mass or clear, colourless, volatile liquid.
Solubility: Miscible with water, with ethanol (96 per cent) and with methylene chloride.
IDENTIFICATION
A. A 100 g/L solution is strongly acid (2.2.4).
B. To 0.03 mL add 3 mL of water R and neutralise with dilute sodium hydroxide  solution R. The solution gives reaction (b) of acetates (2.3.1).
TESTS
Solution S: Dilute 20 mL to 100 mL with distilled water.
Appearance:  The substance to be examined is clear and colourless.
Freezing point:  Minimum 14.8 °C.
Reducing substances: To 5.0 mL add 10.0 mL of water and mix. To 5.0 mL of this solution add 6 mL of sulfuric acid, cool and add 2.0 mL of 0.0167 M potassium dichromate. Allow to  stand for 1 min and add 25 mL of water and 1 mL of a freshly prepared 100 g/L  solution of potassium iodide. Titrate with 0.1 M sodium thiosulfate, using 1.0 mL of  starch solution as indicator. Not less than 1.0 mL of 0.1 M sodium thiosulfate  solution is required.
Chlorides: Maximum 25 mg/L.
Sulfates: Maximum 50 mg/L, determined on solution S.
Iron: Maximum 5 ppm.
Heavy metals: Maximum 5 ppm.
Residue on evaporation: Maximum 0.01 per cent.
Evaporate 20 g to dryness on a water-bath and dry at 100-105 °C. The residue  weighs a maximum of 2.0 mg.