Magnesium bicarbonate

Magnesium bicarbonate or magnesium hydrogen carbonate, Mg(HCO3)2, is the bicarbonate salt of magnesium. It can be formed through the reaction of dilute solutions of carbonic acid (such as seltzer water) and magnesium hydroxide (milk of magnesia).

Magnesium bicarbonate
Magnesium bicarbonate
IUPAC name
Magnesium hydrogen carbonate
Other names
Magnesium bicarbonate
3D model (JSmol)
ECHA InfoCard 100.016.582
E number E504(ii) (acidity regulators, ...)
Molar mass 146.34 g/mol
0.077 g / (100 mL)
Related compounds
Other cations
Calcium bicarbonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

It can be prepared through the synthesis of Magnesium acetate and Sodium bicarbonate Mg(CH3COO)2 + 2NaHCO3 = Mg(HCO3)2 + 2CH3COONa

Magnesium bicarbonate exists only in aqueous solution. Magnesium does not form solid bicarbonate as like Lithium. To produce it, a suspension of magnesium hydroxide is treated with pressurized carbon dioxide, producing a solution of magnesium bicarbonate:[1]

Mg(OH)2 + 2 CO2 → Mg(HCO3)2

Drying the resulting solution causes the magnesium bicarbonate to decompose, yielding magnesium carbonate, carbon dioxide, and water:

Mg2+ + 2 HCO3 → MgCO3 + CO2 + H2O


  1. ^ Margarete Seeger; Walter Otto; Wilhelm Flick; Friedrich Bickelhaupt; Otto S. Akkerman. "Magnesium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a15_595.pub2.