Barium hydroxide

Barium hydroxide

Chembox new
Name = Barium hydroxide
Section1 = Chembox Identifiers
CASNo = 17194-00-2
RTECS = CQ9200000

Section2 = Chembox Properties
Formula = Ba(OH)2
MolarMass = 171.342 g/mol (anhydrous)
189.36 g/mol (monohydrate)
315.46 g/mol (octahydrate)
Appearance = white solid
Solubility = 5.6 g/100 g (octahydrate & anhydrous)
Solvent = other solvents
SolubleOther = low
MeltingPt = 78 °C (octahydrate)
>408 °C (anhydrous)
BoilingPt = 780 °C
pKb = -2.02

Section3 = Chembox Structure
Coordination =
CrystalStruct = octahedral

Section4 = Chembox Thermochemistry
DeltaHf = −944.7 kJ/mol

Section7 = Chembox Hazards
EUClass = Harmful (Xn)
NFPA-H = 3
RPhrases = R20/22
SPhrases = S2, S28
FlashPt = non-flammable

Section8 = Chembox Related
OtherAnions = Barium oxide
Barium peroxide
OtherCations = Calcium hydroxide
Strontium hydroxide

Barium hydroxide is the chemical compound with the formula Ba(OH)2. Also known as baryta, it is one of the principal compounds of barium. The white granular monohydrate is the usual commercial form.


Barium hydroxide can be prepared by dissolving barium oxide (BaO) in water.:BaO + 9H2O → Ba(OH)2·8H2OIt crystallises as the octahydrate, which converts to the monohydrate upon heating in air. At 100 °C in a vacuum, the monohydrate gives BaO. [(1960). "Gmelins Handbuch der anorganischen Chemie (8. Aufl.)", Weinheim: Verlag Chemie, p. 289.]


Barium hydroxide is used in analytical chemistry for the titration of weak acids, particularly organic acids. Its clear aqueous solution is guaranteed to be free of carbonate, unlike those of sodium hydroxide and potassium hydroxide, as barium carbonate is insoluble in water. This allows the use of indicators such as phenolphthalein or thymolphthalein (with alkaline colour changes) without the risk of titration errors due to the presence of weakly basic carbonate ions. [VogelQuantitative]

Barium hydroxide is used in organic synthesis as a strong base, for example for the hydrolysis of esters [Meyer, K.; Bloch, H. S. (1945). " [ Naphthoresorcinol] ". "Org. Synth." 25: 73; "Coll. Vol." 3: 637.] and nitriles. [Brown, G. B. (1946). " [ Methylsuccinic acid] ". "Org. Synth." 26: 54; "Coll. Vol." 3: 615.] [Ford, Jared H. (1947). " [ β-Alanine] ". "Org. Synth." 27: 1; "Coll. Vol." 3: 34.] [Anslow, W. K.; King, H.; Orten, J. M.; Hill, R. M. (1925). " [ Glycine] ". "Org. Synth." 4: 31; "Coll. Vol." 1: 298.]


It has been used to hydrolyse one of the two equivalent ester groups in dimethyl hendecanedioate. [Durham, L. J.; McLeod, D. J.; Cason, J. (1958). " [ Methyl hydrogen hendecanedioate] ". "Org. Synth." 38:55; "Coll. Vol." 4:635.]

It is also used in the preparation of cyclopentanone, [Thorpe, J. F.; Kon, G. A. R. (1925). " [ Cyclopentanone] ". "Org. Synth." 5: 37; "Coll. Vol." 1: 192.] diacetone alcohol [Conant, J. B.; Tuttle, Niel. (1921). " [ Diacetone alcohol] ". "Org. Synth." 1: 45; "Coll. Vol." 1: 199.] and D-Gulonic γ-lactone. [Karabinos, J. V. (1956). " [ γ-lactone] ". "Org. Synth." 36: 38; "Coll. Vol." 4: 506.]


Barium hydroxide is used in a demonstration of endothermic reactions since, when mixed with an ammonium salt, the reaction becomes cold as heat is absorbed from the surroundings.

Miscellaneous applications

*Under the name baryta it is used in homeopathic remedies.
*It is also used to clean up acid spills.


Barium hydroxide presents the same hazards as other strong bases and as other water-soluble barium compounds: it is corrosive and toxic.


External links

* [ Material Safety Data Sheet (MSDS)]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • barium hydroxide — n. a toxic, white powder or crystalline material, Ba(OH) 2, used in making lubricating oils and greases, soaps, and insecticides and in sugar refining, water softening, etc …   English World dictionary

  • barium hydroxide — bario hidroksidas statusas T sritis chemija formulė Ba(OH)₂ atitikmenys: angl. barium hydroxide; caustic baryta; hydrated baryta rus. бария гидроксид; бария гидроокись; едкий барит …   Chemijos terminų aiškinamasis žodynas

  • barium hydroxide — noun white poisonous crystals; made by dissolving barium oxide in water • Hypernyms: ↑baryta * * * noun : a strong toxic base Ba(OH)2.8H2O obtained usually as colorless crystals by dissolving barium oxide in water and used chiefly in making… …   Useful english dictionary

  • barium hydroxide — Chem. baryta (def. 2). Also called barium hydrate. * * * …   Universalium

  • Barium hydroxide (data page) — This page provides supplementary chemical data on barium hydroxide. Material Safety Data Sheet * [ whole=whole start=0 SIRI] * [ Science Stuff]… …   Wikipedia

  • barium hydroxide lime — [USP] a mixture of barium hydroxide octahydrate and calcium hydroxide used as a carbon dioxide absorbent in the administration of anesthetic gases and oxygen …   Medical dictionary

  • barium hydrate — barium hydroxide Ba(OH)2, a crystalline soluble base employed as a test for sulfates …   Medical dictionary

  • Barium oxide — Chembox new Name = Barium oxide OtherNames = Barium monoxide; barium protoxide; calcined baryta Section1 = Chembox Identifiers CASNo = 1304 28 5 Section2 = Chembox Properties Formula = BaO MolarMass = 153.3 g/mol Appearance = white solid Density …   Wikipedia

  • Hydroxide — Lewis structure of the hydroxide ion showing three lone pairs on the oxygen atom …   Wikipedia

  • Barium chloride — Chembox new Name = Barium chloride ImageFile = Barium chloride.jpg ImageSize = 200px ImageName = Barium chloride Section1 = Chembox Identifiers CASNo = 10361 37 2 Section2 = Chembox Properties Formula = BaCl2 (anhydrous) BaCl2 middot;2H2O… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”