Magnesium Sulphate Heptahydrate

Grade

IP

BP/EP

USP

Description

Colourless crystals or white crystalline powder, odourless.

White or almost white crystalline powder, or brilliant, colourless crystals.

Small, colorless crystals

Solubility

Freely soluble in water, very soluble in boiling water, practically insoluble in ethanol (95%)

Freely soluble in water, very soluble in boiling water, practically insoluble in ethanol (96%)

Freely ( and slowly ) soluble in glycerine; very soluble in boiling water; sparingly soluble in alcohol

Identification

Gives reactions of sulphate and  for magnesium salt

Gives reactions of sulphates and  for magnesium

Gives responds to sulphate and

magnesium

Appearance of solution

Solution is clear and colourless

Solution is clear and colourless

-

Arsenic

Max. 2 PPM

Max. 2 PPM

Max 3 ppm

Barium

-

-

No turbidity is produced within 15 min

Calcium

-

-

Not more than a slight turbidity is produced within 5 min

Acidity or Alkalinity

0.2 ml of  0.01M of HCl or 0.01M of NaOH

0.2 ml of  0.01M of HCl or 0.01M of NaOH

-

Iron

Max. 200 ppm

Max. 20 ppm

2ug/g

Heavy Metals

Max. 10 ppm

Max. 10 ppm

0.003%

Chloride

Max. 300 ppm

Max. 300 ppm

0.14%

Carbonate

No effervescence occurs

Ph

-

-

5.0  to 9.2

Sulphate

-

-

0.6%

Acid-insoluble substances

-

-

0.2%

Soluble substances

-

-

1.5%

Lead

-

-

Max 5 ppm

Selenium

-

-

0.003%

Organic volatile impurities

-

-

Meets the requirement

Limit of Nitrate

-

-

The blue color persist for not less than 5 min

Loss on ignition

-

-

20.0% to 27.0%

Loss on Drying

48.0 % TO 52.0 %

48.0 % TO 52.0 %

Max 2%

Assay on Dry Basis

99.0 TO 100.5%

99.0 TO 100.5%

99.0% to 100.5%