Magnesium Hydrogen Carbonate, Mg(HCO₃)₂

When magnesium carbonate dissolves in water containing carbon dioxide, the reaction

MgCO₃+H₂O+CO₂ = Mg(HCO₃)₂

presumably occurs. To obtain a pure solution, magnesia alba can be dissolved in carbonated water and magnesium carbonate precipitated by boiling. The precipitate, thus freed from sodium carbonate, is re- dissolved in carbonated water, and the process, if necessary, repeated. Carbon dioxide can also be passed through distilled water containing pure magnesia in suspension.