Strontium hydroxide, Sr(OH)
2, is a caustic
alkali
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a ...
composed of one
strontium
Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is ex ...
ion and two
hydroxide ions. It is synthesized by combining a strontium
salt with a
strong base
In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances that react with acids, as originally proposed by G.-F. Rou ...
. Sr(OH)
2 exists in
anhydrous
A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...
,
monohydrate, or octahydrate form.
Preparation
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(NO
3)
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.
Applications
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
Strontium hydroxide is a severe skin, eye and respiratory irritant. It is harmful if swallowed.
References
External links
*http://www.chemicalland21.com/industrialchem/inorganic/STRONTIUM%20HYDROXIDE.htm
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Strontium compounds
Hydroxides