|Molar mass||121.63 g/mol (anhydrous)
139.65 g/mol (monohydrate)
265.76 g/mol (octahydrate)
|Appearance||prismatic colourless crystals
|Density||3.625 g/cm3 (anhydrous)
1.90 g/cm3 (octahydrate)
|Melting point||535 °C (995 °F; 808 K) (anhydrous, 375C 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 (20 °C)
21.83 g/100 mL (100 °C) 
|Solubility||insoluble in acetone
soluble in acid, NH4Cl
|Crystal structure||tetragonal (octahydrate)|
|EU Index||Not listed|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
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.
Because Sr(OH)2 is very slightly soluble in 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 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.
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.
Strontium hydroxide is a severe skin, eye and respiratory irritant. It is harmful if swallowed.