Magnesium carbonate



Safety data
Other names Lansfordite
White gold:
Identifiers
CAS number 546-93-0
RTECS number OM2470000
Properties
Molecular formula MgCO3
Molar mass 84.32 g/mol
Appearance white solid
Density 2.958 g/cm3, solid
Melting point

350 °C decomp.

Solubility in water 10.6 mg/100 ml
Structure
Crystal structure Trigonal
Thermochemistry
Std enthalpy of
formation ΔfHo298 		-1111.69 kJ/mol
Standard molar
entropy So298 		65.84 J.K−1.mol−1
Related Compounds
Other cations Barium carbonate
Related compounds Hydromagnesite
Dypingite
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Magnesium carbonate, MgCO3, is a white minerals. In addition, MgCO3 has a variety of applications.

Properties

The most common magnesium carbonate forms are the monoclinic crystals.

Reactions

Although magnesium carbonate is ordinarily obtained by mining the mineral magnesite, the trihydrate salt, MgCO3·3H2O, can be prepared by mixing solutions of pressure (3.5 to 5 atm) below 50 °C, which gives soluble magnesium bicarbonate:

Mg(OH)2 + 2 CO2 → Mg(HCO3)2

Following the filtration of the solution, the filtrate is dried under vacuum to produce magnesium carbonate as a hydrated salt:

Mg2+ + 2 HCO3- → MgCO3 + CO2 + H2O

When dissolved with carbon dioxide:

MgCO3 + 2 HCl → MgCl2 + CO2 + H2O
MgCO3 + H2SO4 → MgSO4 + CO2 + H2O

At high temperatures, MgCO3 decomposes to calcining:

MgCO3 → MgO + CO2

Uses

Magnesite and antacid and as an additive in table salt to keep it free flowing.

In 1911 MgCO3 was first added to salt to make it flow more freely.[1]

Magnesium carbonate, most often referred to as 'chalk', is used as a drying agent for hands in rock climbing, gymnastics, and weight lifting.

References

  1. ^ Morton Salt FAQ.
  • Patnaik, Pradyot (2003). Handbook of Inorganic Chemicals. New York: McGraw Hill. 
  • Trotman-Dickenson, A.F "(ed.)" (1973). Comprehensive Inorganic Chemistry. Oxford: Pergamon Press. 
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Magnesium_carbonate". A list of authors is available in Wikipedia.