Barium hydroxide
General
Molecular formula	Ba(OH)2
Molar mass	171.342 g/mol (anhydrous) 189.36 g/mol (monohydrate) 315.46 g/mol (octahydrate)
Appearance	white solid
CAS number	[17194-00-2] (anhydrous) [22326-55-2] (monohydrate) [12230-71-6] (octahydrate)
Properties
Density (solid)	2.2 g/cm3 (anhydrous) 3.74 g/cm3 (monohydrate)
Solubility in water	5.6 g/100 g
Other solvents	low
Melting point	78 °C (octahydrate) >408 °C (anhydrous)
Boiling point	780 °C
Basicity (pKb)	-2.02
Structure
Coordination geometry	?
Crystal structure	octahedral
Thermodynamic data
Std enthalpy change of formation, ΔfHosolid	−944.7 kJ/mol
Standard molar entropy, Sosolid	100±6 J.K−1.mol−1
Heat of fusion	93.3805 (anhydrous)
Hazards
MSDS	External MSDS
EU classification	Harmful (Xn)
NFPA 704	0 3 0
R-phrases	R20/22
S-phrases	(S2), S28
Flash point	non-flammable
RTECS number	CQ9200000
Supplementary data page
Structure and properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	Barium oxide Barium peroxide
Other cations	Calcium hydroxide Strontium hydroxide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

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. This article or section does not cite any references or sources. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... It has been suggested that this article or section be merged with Solution. ... This article describes water from a scientific and technical perspective. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... Italic text This article is about the boiling point of liquids. ... The acid dissociation constant (Ka), also known as the acidity constant or the acid-ionization constant, is a specific equilibrium constant for the reaction of an acid with its conjugate base in aqueous solution [1]. // When an acid dissolves in water, it partly dissociates forming hydronium ions and its conjugate... The coordination geometry of an atom is the geometrical pattern formed by its neighbors in a molecule or a crystal. ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 atmosphere... In chemistry, the standard molar entropy is the entropy content of one mole of substance, under conditions of standard temperature and pressure. ... Heat of fusion is the amount of heat energy which must be absorbed or lost for 1 gram of a substance to change states from a solid to a liquid or vice versa. ... An example MSDS in a US format provides guidance for handling a hazardous substance and information on its composition and properties. ... This page provides supplementary chemical data on barium hydroxide. ... Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (as amended) is the main European Union law concerning chemical safety. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links NFPA_704. ... R-phrases are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous substances and preparations. ... S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. ... The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture with air. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... This page provides supplementary chemical data on barium hydroxide. ... This page provides supplementary chemical data on barium hydroxide. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... The relative dielectric constant of a material under given conditions is a measure of the extent to which it concentrates electrostatic lines of flux. ... This page provides supplementary chemical data on barium hydroxide. ... This page provides supplementary chemical data on barium hydroxide. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the IR region of the EM spectrum. ... It has been suggested that NMR Data Processing be merged into this article or section. ... Mass spectrometry (also known as mass spectroscopy (deprecated)[1] or informally, mass-spec and MS) is an analytical technique used to measure the mass-to-charge ratio of ions. ... An electrostatic potential map of the nitrate ion (NO3−). Areas coloured red are lower in energy than areas colored yellow An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ... ... Barium peroxide is a grey-white compound and oxidising agent. ... An electrostatic potential map of the nitrate ion (NO3−). Areas coloured red are lower in energy than areas colored yellow An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ... It has been suggested that Portlandite be merged into this article or section. ... // Preparation Uses Used chiefly in the refining of beet sugar. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... A chemical compound is a chemical substance of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ... This article or section does not cite any references or sources. ... General Name, Symbol, Number barium2, Ba, 56 Chemical series alkaline earth metals Group, Period, Block 2, 6, s Appearance silvery white Standard atomic weight 137. ... Hydrate is a term which means different things in inorganic chemistry and organic chemistry. ...

Preparation

Barium hydroxide can be prepared by dissolving barium oxide (BaO) in water. ...

BaO + 9H₂O → Ba(OH)₂·8H₂O

It crystallises as the octahydrate, which converts to the monohydrate upon heating in air. At 100 °C in a vacuum, the monohydrate gives BaO.^[1]

Uses

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.^[2] This article does not cite any references or sources. ... A weak acid is an acid that does not fully ionize in solution; that is, if the acid was represented by the general formula HA, then in aqueous solution a significant amount of undissolved HA still remains. ... An organic acid is an organic compound that is an acid. ... Sodium hydroxide (NaOH), also known as lye or caustic soda or sodium hydrate, is a caustic metallic base. ... The chemical compound potassium hydroxide, (KOH) sometimes known as caustic potash, potassa, potash lye, and potassium hydrate, is a metallic base. ... Barium carbonate (BaCO3), also known as witherite, is a chemical compound used in rat poison, bricks and cement. ... Phenolphthalein is a sensitive chemical with the formula C20H14O4 (often written as HIn in shorthand notation). ... Thymolphthalein is an acid-base (pH) indicator. ... Titration setup: the titrant drops from the burette into the analyte solution in the flask. ... The word error has different meanings in different domains. ... In organic chemistry, a carbonate is a salt of carbonic acid. ...

Barium hydroxide is used in organic synthesis as a strong base, for example for the hydrolysis of esters^[3] and nitriles.^[4][5][6]

It has been used to hydrolyse one of the two equivalent ester groups in dimethyl hendecanedioate.^[7] Image File history File links Size of this preview: 800 × 154 pixelsFull resolution (1198 × 230 pixel, file size: 3 KB, MIME type: image/png) Description: Preparation of 2-Carboxy-1,3-dihydroxynaphthalene. ... Image File history File links Size of this preview: 800 × 146 pixelsFull resolution (8185 × 1498 pixel, file size: 44 KB, MIME type: image/png) Description: Preparation of methylsuccinic acid. ...

It is also used in the preparation of cyclopentanone,^[8] diacetone alcohol^[9] and D-Gulonic γ-lactone.^[10] Pentanone is an organic compound with a linear form and a cyclic form, cyclopentanone. ... Diacetone alcohol is a chemical compound with the formula CH3C(O)CH2C(OH)(CH3)2. ...

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. Image File history File links Size of this preview: 800 × 145 pixelsFull resolution (7786 × 1407 pixel, file size: 42 KB, MIME type: image/png) Description: Preparation of diacetone alcohol. ... In Chemistry an endothermic reaction is one in which the reactants have less energy than the products, and thus a net input of energy, usually in the form of heat, is required. ... Fumes from hydrochloric acid and ammonia forming a white cloud of ammonium chloride Ammonium is also an old name for the Siwa oasis in western Egypt. ... For other uses, see Heat (disambiguation) In physics, heat, symbolized by Q, is energy transferred from one body or system to another as a result of a difference in temperature. ... In a thermodynamics problem, the surroundings, or environment, are anything not part of the system. ...

Miscellaneous applications

• Under the name baryta it is used in homeopathic remedies.
• It is also used to clean up acid spills.
• Also under the name of baryta it is used in the production of photographic paper for printing.

Until the advent of digital photographic processes, the sole meaning of Photographic Paper was paper coated with light-sensitive chemicals. ...

Safety

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

References

1. ^ Gmelins Handbuch der anorganischen Chemie (8. Aufl.), Weinheim:Verlag Chemie, 1960, p. 289.
2. ^ Mendham, J.; Denney, R. C.; Barnes, J. D.; Thomas, M.J.K.; Denney, R. C.; Thomas, M. J. K. Vogel's Quantitative Chemical Analysis (6th Edn.) New York:Prentice Hall. ISBN 0-582-22628-7.
3. ^ Meyer, K.; Bloch, H. S. (1945). "Naphthoresorcinol". Org. Synth. 25:73; Coll. Vol. 3:637.
4. ^ Brown, G. B. (1946). "Methylsuccinic acid". Org. Synth. 26:54; Coll. Vol. 3:615.
5. ^ Ford, Jared H. (1947). "β-Alanine". Org. Synth. 27:1; Coll. Vol. 3:34.
6. ^ Anslow, W. K.; King, H.; Orten, J. M.; Hill, R. M. (1925). "Glycine". Org. Synth. 4:31; Coll. Vol. 1:298.
7. ^ Durham, L. J.; McLeod, D. J.; Cason, J. (1958). "Methyl hydrogen hendecanedioate". Org. Synth. 38:55; Coll. Vol. 4:635.
8. ^ Thorpe, J. F.; Kon, G. A. R. (1925). "Cyclopentanone". Org. Synth. 5:37; Coll. Vol. 1:192.
9. ^ Conant, J. B.; Tuttle, Niel. (1921). "Diacetone alcohol". Org. Synth. 1:45; Coll. Vol. 1:199.
10. ^ Karabinos, J. V. (1956). "D-Gulonic γ-lactone". Org. Synth. 36:38; Coll. Vol. 4:506.

Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ... Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ... Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ... Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ... Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ... Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ... Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ... Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ...

External links

• Material Safety Data Sheet (MSDS)