Strontium hydroxide

Summary

Strontium hydroxide, Sr(OH)2, is a caustic alkali composed of one strontium ion and two hydroxide ions. It is synthesized by combining a strontium salt with a strong base. Sr(OH)2 exists in anhydrous, monohydrate, or octahydrate form.

Strontium hydroxide
Identifiers
  • 18480-07-4 checkY
  • 1311-10-0 (octahydrate) checkY
3D model (JSmol)
  • Interactive image
ChEBI
  • CHEBI:35105 checkY
ChemSpider
  • 79094 checkY
ECHA InfoCard 100.038.501 Edit this at Wikidata
EC Number
  • 242-367-1
847042
  • 87672
UNII
  • EPK818UET5 checkY
  • T2B33T08R4 (octahydrate) checkY
  • DTXSID60893975 Edit this at Wikidata
  • InChI=1S/2H2O.Sr/h2*1H2;/q;;+2/p-2 checkY
    Key: UUCCCPNEFXQJEL-UHFFFAOYSA-L checkY
  • InChI=1/2H2O.Sr/h2*1H2;/q;;+2/p-2
    Key: UUCCCPNEFXQJEL-NUQVWONBAP
  • [Sr+2].[OH-].[OH-]
Properties
Sr(OH)2
Molar mass 121.63 g/mol (anhydrous)
139.65 g/mol (monohydrate)
265.76 g/mol (octahydrate)
Appearance prismatic colourless crystals
deliquescent
Density 3.625 g/cm3 (anhydrous)
1.90 g/cm3 (octahydrate)
Melting point 535 °C (995 °F; 808 K) (anhydrous, 375K for octahydrate)
Boiling point 710 °C (1,310 °F; 983 K) decomposes (anhydrous)
0.41 g/100 mL (0 °C)
1.77 g/100 mL (40 °C)
21.83 g/100 mL (100 °C) [1]
Solubility insoluble in acetone
soluble in acid, NH4Cl
Basicity (pKb) 0.3 (first OH), 0.83 (second OH)[2]
−40.0·10−6 cm3/mol
Structure
tetragonal (octahydrate)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
1
0
1
Flash point Non-flammable
Related compounds
Other anions
Strontium oxide
Strontium peroxide
Other cations
Beryllium hydroxide
Magnesium hydroxide
Calcium hydroxide
Barium hydroxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Preparation edit

Because Sr(OH)2 is slightly soluble in cold water, its preparation can be easily carried out by the addition of a strong base such as NaOH or KOH, drop by drop to a solution of any soluble strontium salt, most commonly Sr(NO3)2 (strontium nitrate). The Sr(OH)2 will precipitate out as a fine white powder. From here, the solution is filtered, and the Sr(OH)2 is washed with cold water and dried.[3]

Applications edit

Strontium hydroxide is used chiefly in the refining of beet sugar and as a stabilizer in plastic. It may be used as a source of strontium ions when the chlorine from strontium chloride is undesirable. Strontium hydroxide absorbs carbon dioxide from the air to form strontium carbonate.

Safety edit

Strontium hydroxide is a severe skin, eye and respiratory irritant. It is harmful if swallowed.

References edit

  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  2. ^ "Sortierte Liste: pKb-Werte, nach Ordnungszahl sortiert. - Das Periodensystem online" (in German).
  3. ^ Brauer, Georg (1963). Handbook Of Preparative Inorganic Chemistry. Academic Press. p. 935.

External links edit

  • http://www.chemicalland21.com/industrialchem/inorganic/STRONTIUM%20HYDROXIDE.htm