Magnesium sulfate heptahydrate (MgSO4•7H2O)-Crystalline

Characteristic

 

Magnesium sulfate is an inorganic salt with the formula MgSO4(H2O)x where 0 ≤ x ≤ 7. It is often encountered as the heptahydrate sulphate mineral epsomite (MgSO4·7H2O), commonly called Epsom salt.




Chemical formula:MgSO4

Molar mass:120.366 g/mol (anhydrous);138.38 g/mol (monohydrate);174.41 g/mol (trihydrate);210.44 g/mol (pentahydrate);228.46 g/mol (hexahydrate);246.47 g/mol (heptahydrate)

Appearance:white crystalline solid

Odor:odorless

Density:2.66 g/cm3 (anhydrous);2.445 g/cm3 (monohydrate);1.68 g/cm3 (heptahydrate);1.512 g/cm3 (11-hydrate)

Melting point:anhydrous decomposes at 1,124°C;monohydrate decomposes at 200°C;heptahydrate decomposes at 150°C;undecahydrate decomposes at 2°C

Solubility in water:anhydrous:26.9 g/100 mL (0 °C);35.1 g/100 mL (20 °C);50.2 g/100 mL (100 °C)

heptahydrate:113 g/100 mL (20 °C);Solubility 1.16 g/100 mL (18°C, ether)

slightly:soluble in alcohol, glycerol;insoluble in acetone

Magnetic susceptibility (χ):−50·10−6 cm3/mol

Refractive index (nD):1.523 (monohydrate);1.433 (heptahydrate)

Crystal structure:monoclinic (hydrate)

 


Application

 

Magnesium sulfate produced by appropriate process finds use in several pharmaceutical preparations of magnesium, usually known as epsom salt. It is used as a micronutrient in agriculture, brewing salt in production of certain alcoholic products, electrolyte to prepare metal salts, coagulant, and ingredient in bath salts for use in floatation therapy.