Barium hydroxide

Barium hydroxide Basic information
Description Chemical Properties Uses Production Methods References
Product Name:Barium hydroxide
Synonyms:Ba(OH)2;Barium hydroxide (Ba(OH)2);Barium hydroxide, alpha;bariumdihydroxide;bariumhydroxide(ba(oh)2);Bariumhydroxide,anhydrous;BARIUM HYDRATE;BARIUM HYDROXIDE
CAS:17194-00-2
MF:BaH2O2
MW:171.34
EINECS:241-234-5
Product Categories:metal hydroxide;Inorganics;Barium SaltsChemical Synthesis;Inorganic Bases;Metal and Ceramic Science;Salts;Synthetic Reagents;Base SolutionsChemical Synthesis;By Reference Material;Inorganic BasesVolumetric Solutions;Reference Material Hydrochloric acid;Titration;Volumetric Solutions;Chemical Synthesis;Industrial/Fine Chemicals;BARIUM, INORGANIC SALT;17194-00-2
Mol File:17194-00-2.mol
Barium hydroxide Structure
Barium hydroxide Chemical Properties
Melting point >300 °C(lit.)
Boiling point decomposes at 1032 (calculated) [KNA91]
density 2.2 g/mL at 25 °C(lit.)
solubility Aqueous Acid (Slightly), Water (Slightly)
form Solid
color Clear
Odorno odor
PH11.27(1 mM solution);12.22(10 mM solution);13.08(100 mM solution)
Water Solubility Soluble in water.
Sensitive Air Sensitive & Hygroscopic
Merck 14,977
Exposure limitsACGIH: TWA 0.5 mg/m3
NIOSH: IDLH 50 mg/m3; TWA 0.5 mg/m3
Stability:Stable. Incompatible with acids, carbon dioxide, moisture.
InChIKeyRQPZNWPYLFFXCP-UHFFFAOYSA-L
CAS DataBase Reference17194-00-2(CAS DataBase Reference)
NIST Chemistry ReferenceBarium dihydroxide(17194-00-2)
EPA Substance Registry SystemBarium hydroxide (Ba(OH)2) (17194-00-2)
Safety Information
Hazard Codes C,Xi,Xn
Risk Statements 36/37/38-34-20/22-36/38-41-35-22
Safety Statements 26-36/37/39-45-36/37
RIDADR UN 3262 8/PG 2
WGK Germany 1
RTECS CQ9200000
TSCA Yes
HazardClass 8
PackingGroup III
HS Code 2805191000
Hazardous Substances Data17194-00-2(Hazardous Substances Data)
ToxicityLD50 ipr-mus: 255 mg/kg GTPZAB 28(6),45,84
MSDS Information
ProviderLanguage
SigmaAldrich English
ALFA English
Barium hydroxide Usage And Synthesis
DescriptionBarium hydroxide is a kind of barium base. It has many kinds of applications. It can be used as the precursor for the preparation of other barium compounds. Its monohydrate form can be used to dehydrate and remove sulfate in many products. In laboratory, it can be used in analytic chemistry for the titration assay of organic acid. In organic synthesis, it is a strong base used for the hydrolysis of esters and nitriles. It is also a useful catalyst of organic synthesis. Other applications also include acting as an interlayer between zinc oxide and a luminescent conjugated polymer for light-emitting diodes, extracting pure arabinoxylans from water-insoluble cell wall material of wheat flour, removing sulfate and metals from the water and acting as a selective precipitating agent for hemicelluloses.
Chemical Propertiesbarium hydroxide is a white or colorless, poisonous powder or crystalline substance, Ba(OH)2, used for example, in the saponification of fats and the fusing of silicates. Barium hydroxide forms a strong caustic base in aqueous solution. It has many uses, e.g., as a test for sulfides; in pesticides; in the manufacture of alkali and glass.
barium hydroxide, anhydrous
barium hydroxide, anhydrous. the commercially available preparation usually contains 92-95% of the monohydrate and is poisonous. barium hydroxide, monohydrate (barium monohydrate). a white, poisonous, slightly water-soluble, powder, Ba(OH)2.H2O; it is soluble in dilute acids. barium hydroxide, octahydrate is a poisonous white powder, Ba(OH)2.8H2O, that is soluble in water, ethanol, and ether; it absorbs CO2 from the atmosphere. It is used chiefly in organic preparations and analytical chemistry. barium hydroxide,pentahydrate. toxic white fakes, Ba(OH)2.5H2O; uses are the same as those of the octahydrate.
UsesBarium hydroxide, especially the monohydrate, is used to produce organic barium compounds such as additives for oil and stabilizers for plastics. In addition, barium hydroxide is used for. dehydration and deacidification, especially for removing sulfuric acid from fats, oils, waxes, and glycerol. In some applications, e.g., removal of sulfate from water and as starting material for other barium compounds, barium hydroxide to some ex1ent replaces barium carbonate. The earlier use of the hydroxide in some countries forextracting the residual sucrose from molasses is no longer of much significance. The re- cent patent literature describes a procedure in which barium hydroxide is reacted with hydrogen peroxide to produce barium peroxide monohydrate.
Production MethodsThe anhydrous hydroxide has only a secondary industrial importance; the monohydrate and octahydrate are used in industry on a far larger scale.
Barium hydroxide octahydrate is produced by hydration of barium oxide. The barium oxide is suspended in recycled mother lye and heated for several hoursto destroy peroxides. The insolubles, e.g., BaC03 , are separated, and the hydroxide is precipitated by crystallization at low temperatures in stainless steel vessels. The crystals are removed from the mother lye by centrifugation.
Another industrial method is based on the oxidation of a barium sulfide solution. Air is passed into the stirred solution containing barium hydroxide and barium hydrosulfide, the hydrolysis products of barium sulfide, until the hydrosulfide is oxidized to form polysulfide. Then the barium hydroxide octahydrate is crystallized atlow temperatures and separated with a centrifuge. The Polysulfide mother lye is partly recycled, the rest usually processed for other barium compounds.
The monohydrate is generally produced on a commercial scale by dehydration of the octahydrate in heated vacuum driers. A monohydrate of especially high reactivity is obtained with drum driers. This highly reactive monohydrate is particularly suitable for the production of oil additives.
References[1]Wu, Mingmei, et al. "Hydrothermal Synthesis of Tetragonal Barium Titanate from Barium Hydroxide and Titanium Dioxide under Moderate Conditions." Journal of the American Ceramic Society 82.11 (2010):3254-3256.
[2]Meier, Hans, et al. "Barium Hydroxide as a Selective Precipitating Agent for Hemicelluloses." Acta Chemica Scandinavica 12.1(1958):144-146.
[3]Gruppen, H., R. J. Hamer, and A. G. J. Voragen. "Barium hydroxide as a tool to extract pure arabinoxylans from water- insoluble cell wall material of wheat flour." Journal of Cereal Science 13.3(1991):275-290.
[4]Li, Ping Lu, D. Kabra, and R. H. Friend. "Barium Hydroxide as an Interlayer Between Zinc Oxide and a Luminescent Conjugated Polymer for Light-Emitting Diodes." Advanced Functional Materials 22.19(2012):4165–4171.
[5]Bologo, V., J. P. Maree, and F. Carlsson. "Application of magnesium hydroxide and barium hydroxide for the removal of metals and sulphate from mine water." Water Sa 38.1(2012):23-28.
[6]Sinisterra, J. V., A. Fuentes, and J. M. Marinas. "Barium hydroxide as catalyst in organic reactions. 17. Interfacial solid- liquid Wittig-Horner reaction under sonochemical conditions." J.org.chem (1987).
DescriptionBarium Hydroxide occurs as an anhydrate whose prismatic, colorless crystals are very deliquescent. Barium hydroxide can be prepared by dissolving barium oxide (BaO) in water:
BaO+ 9H2O→Ba(OH)2·8H2O
It crystallizes as the octahydrate, which converts to the monohydrate upon heating in air. Barium oxide has been found to react with water vapor at temperatures from 1443 to 1593 K to form gaseous Ba(OH)2 according to the reaction:
BaO(solid)+H2O(gas)→Ba(OH)2(gas)
A better method of preparation involves addition of NaOH to the nitrate. Since barium hydroxide is fairly soluble, it is necessary to evaporate the solution to crystallize Ba(OH)2·8H2O. Ethanol is added to aid in this crystallization. The crystals are washed in cold ethanol to remove sodium ions and then dried.
Chemical PropertiesBarium hydroxide,Ba(OH)2·8H20, is a white crystalline powder, colorless solid composed of monoclinic crystals. It has a melting point of 78°C and is soluble in water and insoluble in acetone. It is used in the fusion of silicates and fat saponification.
Physical propertiesMonohydrate, Ba(OH)2?H2O is a white powder; density 3.743 g/cm3; slightly soluble in water; soluble in dilute mineral acids. Octahydrate, Ba(OH)2?8H2O is a colorless monoclinic crystal; density 2.18 g/cm3 at 16°C; refractive index 1.50; melts at 78°C; vapor pressure 227 torr; loses seven molecules of water of crystallization when its solution is boiled in the absence of atmospheric CO2 forming solid monohydrate; further heating produces anhydrous Ba(OH)2 melting at 407°C; readily dissolves in water (3.76 g/100 g at 20°C and 11.7 g/100 g at 50°C); aqueous solution highly alkaline; also soluble in methanol; slightly soluble in ethanol; insoluble in acetone.
UsesBariium hydroxide is used as a precursor to other barium compounds. It is used in analytical chemistry for titration of weak acids, particularly organic acids. It removes the carbonate in water. It is a strong base, and is used as catalyst in many organic reactions, such as hydrolysis of esters and nitriles, decarboxylation of amino acids, selective hydrolysis of one of the ester groups in dimethyl hendecanedioate, and preparation of cyclopentanone, diacetone alcohol and D-Gulonic gamma-lactone.
UsesCarbon dioxide absorbant.
UsesBarium hydroxide is used in analytical chemistry to titrate weak acids, particularly organic acids. It forms clear aqueous solutions that are free from carbonate, unlike those of the alkali hydroxides, since barium carbonate is insoluble in water. This allows the use of indicators such as phenolphthalein or thymophthalein (with alkaline color changes) without the risk of titration errors due to the presence of weakly basic CO32- ions.Barium hydroxide is used in organic synthesis as a strong base, for example for the hydrolysis of esters and nitriles.It has been used to hydrolyze one of the two equivalent ester groups in dimethyl endecanedioate. It is also used in the preparation of cyclopentanone, diacetone alcohol and d-Gluonic g-lactone.
Barium hydroxide is used as an additive in thermoplastics (such as phenolic resins), rayon and PVC stabilizers to improve plastic properties. This material is used as a general-purpose additive for lubricants and greases. Other industrial applications for barium hydroxide include sugar fabrication, manufacturing soaps, fat saponification, fusing of silicates and chemical synthesis of other barium compounds and organic compounds.
Barium hydroxide is offered for sale both as the octahydrate and the monohydrate. It is available in large quantities commercially.
PreparationBarium hydroxide is made by dissolving barium oxide in hot water. The octahydrate, Ba(OH)2?8H2O, crystallizes upon cooling. It also is prepared by precipitation with caustic soda from an aqueous solution of barium sulfide:
BaS + 2NaOH → Ba(OH)2 + Na2S.
HazardAn acute poison; toxic symptoms are similar to other soluble salts of barium (see Barium).
Flammability and ExplosibilityNotclassified
Safety ProfileA poison by ingestion andintraperitoneal routes. Incompatible with chlorinated rubber.
Barium hydroxide octahydrate Barium Ammonium hydroxide Barium hydroxide, monohydrate, Ba as BaO 78.5-80.5% Barium carbonate Hydroxide BARIUM LACTATE OXALOSUCCINIC ACID BARIUM SALT Barium stearate BARIUM LAURATE BARIUM CYCLOHEXANEBUTYRATE Barium hydroxide Barium oxide malonic acid, barium salt Sodium hydroxide Aluminum hydroxide Calcium hydroxide Barium sulfate

Email:[email protected] [email protected]
Copyright © 2024 Mywellwork.com All rights reserved.