MAGNESIUM HYDROXIDE - (1309-42-8)

Introduction

Name: magnesium hydroxide
* IUPAC
CAS Number: 1309-42-8
Chemical Formula: Mg(OH)2
Molar Mass: 58.31968 g
Mass Percent: Mg 41.675 %; O 54.867 %; H 3.4566 % 

Classification

• inorganic

Uses/Function

• "Antacid; cathartic. Laxative." 1

• "Demand for magnesium hydroxide is growing because of environmental concerns. It is finding new applications as a substitute for NaOH, CaO, and Na2CO3 in treating waster aqueous acid streams, since, because of its poor solubility, it neutralizes acida without the risk of raising the pH of the solution above 9, the limit set by newet pollution restrictions in the United States. In anticipation of moves to phase out organochlorine compounds, manufacturers are also introducing magnesium hydroxide in place of chlorinated organic flame retardants in plastics; endothermic decomposition of Mg(OH)2 to MgO and water vapor stops the spread of combustion." 2

• "Defluoridation [in chemical water analysis]" 3

Solubility

Ksp:5.61·10-12 4

Bonding

Thermochemistry

ΔHf° (s): -221.0 kcal/mol 5 = -924.66 kJ/mol
S° (s): 15.10 cal/(mol•K) 6 = 63.18 J/(mol•K)
ΔGf° (s): -199.3 kcal/mol 7 = -833.87 kJ/mol

Reactions

Safety Information

NFPA 704 Ratings:
Health: 1 - Exposure would cause irritation with only minor residual injury.
Flammability: 0 - Will not burn.
Reactivity: 0 - Normally stable, even under fire exposure conditions, and is not reactive with water.

For More Information

Wikipedia
Journals:
J. F. Goodman, Proc. R. Soc. A 247, 346-352 (1958)
Herman H. Stein and Tobias O. Yellin, Science 157, 96-97 (1967)
J. F. Judkins, Jr. and John S. Hornsby, J. Water Pollut. Control Fed. 50, 2446-2456 (1978)
George C. Whipple and Andrew Mayer Jr., J. Infect. Dis. 3, 151-165 (1906)

Sources

(1) - The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 13th ed.; Budavari, S.; O'Neil, M.J.; Smith, A.; Heckelman, P. E.; Kinneary, J. F., Eds.; Merck & Co.: Whitehouse Station, NJ, 2001; entry 5693.
(2) - Swaddle, T.W. Inorganic Chemistry; Academic Press: San Diego, 1997; p 206.
(3) - Hammer, Mark J. Water and Wastewater Technology, 2nd ed.; Prentice Hall: Englewood Cliffs, NJ, 1986; p 9.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 8:119-8:122.
(5) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(6) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(7) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.