Difference between revisions of "Magnesium chloride"

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===Relevant Sciencemadness threads===
===Relevant Sciencemadness threads===
*[http://www.sciencemadness.org/talk/viewthread.php?tid=41540 failed attempt for magnesium chloride.]
*[http://www.sciencemadness.org/talk/viewthread.php?tid=41540 failed attempt for magnesium chloride.]
*[http://www.sciencemadness.org/talk/viewthread.php?tid=44622  Magnesium Chloride to Magnesium Metal]
'''[http://www.sciencemadness.org/talk/viewthread.php?tid=44622  Magnesium Chloride to Magnesium Metal]
[[Category:Chemical compounds]]
[[Category:Chemical compounds]]
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[[Category:Easily prepared chemicals]]
[[Category:Easily prepared chemicals]]
[[Category:Hygroscopic compounds]]

Revision as of 19:26, 27 January 2016

Magnesium chloride
IUPAC name
Magnesium chloride
Systematic IUPAC name
Magnesium chloride
Jmol-3D images Image
Molar mass 95.211 g/mol (anhydrous)
203.31 g/mol (hexahydrate)
Appearance white or colorless 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)
52.9 g/100 mL (0 °C)
54.3 g/100 mL (20 °C)
72.6 g/100 mL (100 °C)
167 g/100 mL (20 °C)
Solubility slightly soluble in acetone, pyridine
Solubility in ethanol 7.4 g/100 mL (30 °C)
89.88 J/mol K
-641.1 kJ/mol
Safety data sheet ICSC 0764
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
2800 mg/kg (oral, rat)
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Magnesium chloride also known as Nigari is a chemical compounds with the formula MgCl2.



Magnesium chloride will react with calcium hydroxide to give magnesium hydroxide and calcium chloride

MgCl2(aq) + Ca(OH)2 → Mg(OH)2(pp) + CaCl2(aq)


Magnesium chloride is a white hygroscopic solid, soluble in water but poorly soluble in ethanol.


Magnesium chloride is available as tofu coagulant, more exactly as "Nigari flakes" or "Nigari salt".

Magnesium chloride sometimes occurs naturally as the mineral bischofite.


Magnesium chloride can be prepared by reacting hydrochloric acid with magnesium or magnesium carbonate.

A cheaper way involves the reaction of magnesium sulfate (Epsom salt) with calcium chloride. The resulting calcium sulfate is filtered off and the magnesium chloride solution is gently heated at 100 °C to remove the water. Since a small amount will hydrolyze, injecting dry hydrogen chloride gas will regenerate the magnesium chloride. Magnesium carbonate can also be used instead of Epsom salt.


  • Make elemental magnesium (electrolysis of molten MgCl2 at over 714 °C, or of an eutectic mixture of MgCl2, KCl, NaCl at 475 °C)
  • Home-made desiccator



Magnesium chloride is deliquescent and its anhydrous form may cause irritations on contact with skin, eyes or mouth.


Because of its hygroscopicity, magnesium chloride must be stored in an air-tight container.


Magnesium chloride can be safely poured down the drain.


Relevant Sciencemadness threads

Magnesium Chloride to Magnesium Metal