Magnesium oxide

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Properties

Magnesium oxide crystals - SEM image (1350x)

General

Name Magnesium oxide
Chemical formula Mg O
Appearance White, powdery, solid

Physical

Formula weight 40.30 g/mol
Melting point 3073 K (2800 °C)
Boiling point 3873 K (3600 °C)
Density 3.58 kg/dm³
Crystal structure Cubic FCC
Solubility 0.00062 g in 100 g water

Thermochemistry

Δ_fH⁰_liquid ? kJ/mol
Δ_fH⁰_solid -601 kJ/mol
S⁰_solid 32.51 J/(mol·K)

Misc.

Thermal conductivity 42 W m^-1K^-1 at 0 °C
Coefficient of thermal expansion 10.8 ×10^-6/K at 0 °C
Specific heat capacity 877 J kg^-1 K^-1
Dielectric constant 9.65 at 1 MHz
Young's modulus 250 GPa
Shear Modulus 155 GPa
Bulk modulus 155 GPa
Poisson's ratio 0.18

Safety

Ingestion Used as an antacid and/or a laxative. Available over-the-counter.
Inhalation Causes irritation of upper respiratory tract.
Skin Causes irritation.
Eyes Causes irritation.

SI units were used where possible. Unless otherwise stated, standard conditions were used.
Disclaimer and references

**Properties**
Magnesium oxide crystals - SEM image (1350x)
General
Name	Magnesium oxide
Chemical formula	Mg O
Appearance	White, powdery, solid
Physical
Formula weight	40.30 g/mol
Melting point	3073 K (2800 °C)
Boiling point	3873 K (3600 °C)
Density	3.58 kg/dm³
Crystal structure	Cubic FCC
Solubility	0.00062 g in 100 g water
Thermochemistry
Δ_fH⁰_liquid	? kJ/mol
Δ_fH⁰_solid	-601 kJ/mol
S⁰_solid	32.51 J/(mol·K)
Misc.
Thermal conductivity	42 W m^-1K^-1 at 0 °C
Coefficient of thermal expansion	10.8 ×10^-6/K at 0 °C
Specific heat capacity	877 J kg^-1 K^-1
Dielectric constant	9.65 at 1 MHz
Young's modulus	250 GPa
Shear Modulus	155 GPa
Bulk modulus	155 GPa
Poisson's ratio	0.18
Safety
Ingestion	Used as an antacid and/or a laxative. Available over-the-counter.
Inhalation	Causes irritation of upper respiratory tract.
Skin	Causes irritation.
Eyes	Causes irritation.
SI units were used where possible. Unless otherwise stated, standard conditions were used. Disclaimer and references

Magnesium oxide

Magnesium oxide is a white solid mineral that occurs naturally as periclase and is a source of magnesium. See also oxide. It has an empirical formula of . It is formed by an ionic bond between one magnesium and one oxygen atom.

Contents

1 Applications
2 Precautions
3 See also
4 External links
5 Suppliers

Applications

It is used by many libraries for preserving/deacidifying books, and as an insulator in industrial cables. It is also used as a medication to relieve heartburn, sour stomach, or acid indigestion. Medical uses of Magnesium oxide also include using it as a short-term laxative, or used to supplement a diet with magnesium.

Magnesium oxide is used as a basic refractory material for lining crucibles.

Magnesium oxide is a principle ingredient in construction materials used for fireproofing.

It is used as a reference white color in colorimetry. The emissivity value is about 0.9

Pressed MgO is used as an optical material. It is transparent from 300 nm to 7 µm. The refractive index is 1.72 at 1 µm. It is sometimes known by the Eastman Kodak trademarked name Irtran-5.

Precautions

Inhalation of magnesium oxide fumes can cause metal fume fever.

External links

[National Pollutant Inventory - Magnesium Oxide Fume Fact Sheet]
[NIH] medecinal use
[Data page at UCL]
[Ceramic data page at NIST]
[Emissivity]

For a full list of external links to MSDSs, spectroscopic data, commercial chemicals suppliers etc. for this compound, see [Chemical sources].

Suppliers

[Harrick Scientific products]
[Lorad chemical] - as an optical coating material
[Morgan Advanced Ceramics]

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