Characteristic

 

Magnesium chloride is the name for the chemical compound with the formula MgCl₂ and its various hydrates MgCl₂(H₂O)_x. These salts are typical ionic halides, being highly soluble in water. 

Chemical formula：MgCl₂

Molar mass：95.211 g/mol (anhydrous);203.31 g/mol (hexahydrate)

Appearance：white or colourless crystalline solid

Density：2.32 g/cm³ (anhydrous);1.569 g/cm³ (hexahydrate)

Melting point：714 °C (1,317 °F; 987 K) 117 °C (243 °F; 390 K) (hexahydrate);on rapid heating: slow heating leads to decomposition from 300 °C (572 °F; 573 K)

Boiling point：1,412 °C (2,574 °F; 1,685 K)

Solubility in water：anhydrous 52.9 g/100 mL (0 °C);54.3 g/100 mL (20 °C);72.6 g/100 mL (100 °C)

hexahydrate:235 g/100 mL (20 °C)

Solubility：slightly soluble in acetone, pyridine

Solubility in ethanol:7.4 g/100 mL (30 °C)

Magnetic susceptibility (χ):−47.4·10⁻⁶ cm³/mol

 

Application

 

It is widely used as a source of magnesium ion, co-factor for many enzymes, for dust control and road stabilization. Also used in wastewater treatment, wallboard, artificial seawater, feed supplement, textiles, paper, fireproofing agents, cements and refrigeration brine. It is an important coagulant, an elution buffer for antibody affinity column purifications.