Title: Magnesium Oxide
CAS Registry Number: 1309-48-4
Additional Names: Magnesia; calcined magnesia; magnesia usta
Trademarks: Magcal; Maglite (Marine Magnesium)
Molecular Formula: MgO
Molecular Weight: 40.30
Percent Composition: Mg 60.31%, O 39.70%
Literature References: Occurs in nature as the mineral periclase. Commercial prepn from magnesite ores: Adams, US 3320029 (1967 to Northwest Magnesite).
Properties: White, very fine, odorless powder. Available in a very bulky form termed "Light" or in a dense form termed "Heavy." Takes up CO2 and H2O from the air, the light form more readily than the heavy. mp 2800°. Highly reflective in visible and near uv region. Combines with water to form magnesium hydroxide. Very slightly sol in pure water, soly increased by CO2; sol in dil acids; insol in alcohol. Imparts a slight alkaline reaction to water. pH of satd aq soln 10.3. Keep well closed.
Melting point: mp 2800°
CAUTION: Potential symptoms of overexposure to fumes are irritation of eyes and nose; metal fume fever (coughing, chest pain and flu-like fever). See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 188.
Use: Manuf refractory crucibles, fire bricks, magnesia cements and boiler scale compounds, "powdered" oils, casein glue. Reflector in optical instruments; white color standard. Insulator at low temp.
Therap-Cat-Vet: Antacid, laxative, in hypomagnesemia.