baco3

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Barium carbonate
Skeletal formula of barium carbonate
Powder of barium carbonate
Names
Other names

Witherite

Identifiers

CAS Number
  • 513-77-9 check

3D model (JSmol)
  • Interactive image
  • Interactive image
ChEBI
  • CHEBI:190439
ChemSpider
  • 10121 check
ECHA InfoCard 100.007.426 Edit this at Wikidata
EC Number
  • 208-167-3

PubChem CID
  • 10563
RTECS number
  • CQ8600000
UNII
  • 6P669D8HQ8 check
UN number 1564

CompTox Dashboard (EPA)
  • DTXSID1029623 Edit this at Wikidata

InChI

  • InChI=1S/CH2O3.Ba/c2-1(3)4;/h(H2,2,3,4);/q;+2/p-2 check

    Key: AYJRCSIUFZENHW-UHFFFAOYSA-L check

  • InChI=1/CH2O3.Ba/c2-1(3)4;/h(H2,2,3,4);/q;+2/p-2

    Key: AYJRCSIUFZENHW-NUQVWONBAT

SMILES

  • [Ba+2].[O-]C([O-])=O

  • C(=O)([O-])[O-].[Ba+2]

Properties

Chemical formula

 BaCO3
Molar mass 197.34 g/mol
Appearance white crystals
Odor odorless
Density 4.286 g/cm3
Melting point 811 °C (1,492 °F; 1,084 K)
polymorphic transformation
Boiling point 1,450 °C (2,640 °F; 1,720 K)
decomposes[1] from 1360 °C

Solubility in water

 16 mg/L (8.8°C)
22 mg/L (18 °C)
24 mg/L (20 °C)
24 mg/L (24.2 °C)[1]

Solubility product (Ksp)

2.58·10−9
Solubility decomposes in acid
insoluble in methanol

Magnetic susceptibility (χ)

 -58.9·10−6 cm3/mol

Refractive index (nD)

 1.676
Structure

Crystal structure

 orthorhombic
Thermochemistry

Heat capacity (C)

 85.35 J/mol·K[1]

Std molar
entropy (S⦵298)

 112 J/mol·K[2]

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Std enthalpy of
formation (ΔfH⦵298)

 -1219 kJ/mol[2]

Gibbs không tính phí energy (ΔfG⦵)

 -1139 kJ/mol[1]
Hazards
GHS labelling:

Pictograms

 GHS07: Exclamation mark[3]

Signal word

 Warning

Hazard statements

 H302[3]
NFPA 704 (fire diamond)

[4]

NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code

2

Flash point Non-flammable
Lethal dose or concentration (LD, LC):

LD50 (median dose)

 418 mg/kg, oral (rat)
Safety data sheet (SDS) ICSC 0777
Related compounds

Other cations

 Beryllium carbonate
Magnesium carbonate
Calcium carbonate
Strontium carbonate
Radium carbonate

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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Infobox references

Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of the most important barium compounds.[5]

Preparation[edit]

Barium carbonate is made commercially from barium sulfide by treatment with sodium carbonate at 60 to tướng 70 °C (soda ash method) or, more commonly carbon dioxide at 40 to tướng 90 °C:

In the soda ash process, an aqueous solution of barium sulfide is treated with sodium carbonate:[5]

BaS + H2O + CO2 → BaCO3 + H2S

Reactions[edit]

Barium carbonate reacts with acids such as hydrochloric acid to tướng size soluble barium salts, such as barium chloride:

BaCO
3 + 2 HCl → BaCl
2 + CO
2 + H
2O

Pyrolysis of barium carbonate gives barium oxide.[6]

Uses[edit]

It is mainly used to tướng remove sulfate impurities from feedstock of the chlor-alkali process. Otherwise it is a common precursor to tướng barium-containing compounds such as ferrites.[5]

Other uses[edit]

Barium carbonate is widely used in the ceramics industry as an ingredient in glazes. It acts as a flux, a matting and crystallizing agent and combines with certain colouring oxides to tướng produce unique colours not easily attainable by other means. Its use is somewhat controversial since it can leach from glazes into food and drink. To reduce toxicity concerns, it is often substituted with strontium carbonate, which behaves in a similar way in glazes but is of lower toxicity.

In the brick, tile, earthenware and pottery industries barium carbonate is added to tướng clays to tướng precipitate soluble salts (calcium sulfate and magnesium sulfate) that cause efflorescence.

References[edit]

  1. ^ a b c d "Barium carbonate".
  2. ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. ISBN 978-0-618-94690-7.
  3. ^ a b Sigma-Aldrich Co., Barium carbonate. Retrieved on 2014-05-06.
  4. ^ Sciences labs MSDS
  5. ^ a b c Kresse, Robert; Baudis, Ulrich; Jäger, Paul; Riechers, H. Hermann; Wagner, Heinz; Winkler, Jochen; Wolf, Hans Uwe (2007). "Barium and Barium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a03_325.pub2.
  6. ^ P. Ehrlich (1963). "Barium Oxide". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY,NY: Academic Press. pp. 933–944.

[1]

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