Strontium hydroxide

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Strontium hydroxide
3D model (JSmol)
ECHA InfoCard 100.038.501 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 242-367-1
PubChem CID
  • InChI=1S/2H2O.Sr/h2*1H2;/q;;+2/p-2 Yes check.svgY
  • InChI=1/2H2O.Sr/h2*1H2;/q;;+2/p-2
  • [Sr+2].[OH-].[OH-]
Molar mass 121.63 g/mol (anhydrous)
139.65 g/mol (monohydrate)
265.76 g/mol (octahydrate)
Appearanceprismatic colourless crystals
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
tetragonal (octahydrate)
NFPA 704 (fire diamond)
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).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)
Infobox references

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 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]


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.

Related Research Articles

In chemistry, an alkali 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 soluble base has a pH greater than 7.0. The adjective alkaline is commonly, and alkalescent less often, used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases.

Acid–base reaction Chemical reaction

An acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.

Hydroxide Chemical compound

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. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. The corresponding electrically neutral compound HO is the hydroxyl radical. The corresponding covalently bound group –OH of atoms is the hydroxy group. Hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry.

Sodium hydroxide Chemical compound with formula 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 Na+
and hydroxide anions OH

Aqueous solution Solution in which the solvent is water

An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be represented as Na+(aq) + Cl(aq). The word aqueous means pertaining to, related to, similar to, or dissolved in, water. As water is an excellent solvent and is also naturally abundant, it is a ubiquitous solvent in chemistry. Aqueous solution is water with a pH of 7.0 where the hydrogen ions and hydroxide ions are in Arrhenius balance.

Base (chemistry) Type of chemical substance

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 which react with acids as originally proposed by G.-F. Rouelle in the mid-18th century.

Potassium hydroxide Inorganic compound with the formula KOH

Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.

Precipitation (chemistry) Chemical process leading to the settling of an insoluble solid from a solution

In aqueous solution, precipitation is the process of transforming a dissolved substance into an insoluble solid from a super-saturated solution. The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemical reagent causing the solid to form is called the precipitant.

Calcium hydroxide Inorganic compound of formula Ca(OH)2

Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca(OH)2. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed or slaked with water. It has many names including hydrated lime, caustic lime, builders' lime, slaked lime, cal, and pickling lime. Calcium hydroxide is used in many applications, including food preparation, where it has been identified as E number E526. Limewater, also called milk of lime, is the common name for a saturated solution of calcium hydroxide.

Barium hydroxide Chemical compound

Barium hydroxide is a chemical compound with the chemical formula Ba(OH)2. The monohydrate (x = 1), known as baryta or baryta-water, is one of the principal compounds of barium. This white granular monohydrate is the usual commercial form.

Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.

Strontium chloride Chemical compound

Strontium chloride (SrCl2) is a salt of strontium and chlorine.

Iron(II) hydroxide Chemical compound

Iron(II) hydroxide or ferrous hydroxide is an inorganic compound with the formula Fe(OH)2. It is produced when iron(II) salts, from a compound such as iron(II) sulfate, are treated with hydroxide ions. Iron(II) hydroxide is a white solid, but even traces of oxygen impart a greenish tinge. The air-oxidised solid is sometimes known as "green rust".

A strong electrolyte is a solution/solute that completely, or almost completely, ionizes or dissociates in a solution. These ions are good conductors of electric current in the solution.

Copper(II) hydroxide Hydroxide of copper

Copper(II) hydroxide is the hydroxide of copper with the chemical formula of Cu(OH)2. It is a pale greenish blue or bluish green solid. Some forms of copper(II) hydroxide are sold as "stabilized" copper(II) hydroxide, although they likely consist of a mixture of copper(II) carbonate and hydroxide. Cupric hydroxide is a strong base, although its low solubility in water makes this hard to observe directly.

Silver oxide Chemical compound

Silver(I) oxide is the chemical compound with the formula Ag2O. It is a fine black or dark brown powder that is used to prepare other silver compounds.

Aluminium nitrate Chemical compound

Aluminium nitrate is a white, water-soluble salt of aluminium and nitric acid, most commonly existing as the crystalline hydrate, aluminium nitrate nonahydrate, Al(NO3)3·9H2O.

Zinc hydroxide Zn(OH)2 is an inorganic chemical compound. It also occurs naturally as 3 rare minerals: wülfingite (orthorhombic), ashoverite and sweetite (both tetragonal).

Strontium sulfate Chemical compound

Strontium sulfate (SrSO4) is the sulfate salt of strontium. It is a white crystalline powder and occurs in nature as the mineral celestine. It is poorly soluble in water to the extent of 1 part in 8,800. It is more soluble in dilute HCl and nitric acid and appreciably soluble in alkali chloride solutions (e.g. sodium chloride).

Calcium nitrite is an inorganic compound with the chemical formula Ca(NO
. In this compound, as in all nitrites, nitrogen is in a +3 oxidation state. It has many applications such as antifreeze, rust inhibitor of steel and wash heavy oil.


  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.