Strontium hydroxide, Sr(OH)₂, is a caustic alkali composed of one strontium

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

and two

hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. I ...

ions. It is synthesized by combining a strontium

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

with a strong base. Sr(OH)₂ exists in anhydrous, 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 Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkali ...

or KOH, drop by drop to a solution of any soluble strontium salt, most commonly Sr(NO₃)₂ (

strontium nitrate Strontium nitrate is an inorganic compound composed of the elements strontium, nitrogen and oxygen with the formula Sr( NO3)2. This colorless solid is used as a red colorant and oxidizer in pyrotechnics. Preparation Strontium nitrate is typical ...

). 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 Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

from

strontium chloride Strontium chloride (SrCl2) is a salt of strontium and chlorine. It is a 'typical' salt, forming neutral aqueous solutions. As with all compounds of strontium, this salt emits a bright red colour in flame, and is commonly used in fireworks to that ...

is undesirable. Strontium hydroxide absorbs

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

from the air to form

strontium carbonate Strontium carbonate (SrCO3) is the carbonate salt of strontium that has the appearance of a white or grey powder. It occurs in nature as the mineral strontianite. Chemical properties Strontium carbonate is a white, odorless, tasteless powder. B ...

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 {{Authority control Strontium compounds Hydroxides