Potassium carbonate

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Potassium carbonate
Potassium carbonate.svg
Potassium-carbonate-xtal-3D-SF.png
Potassium carbonate.jpg
Names
IUPAC name
Potassium carbonate
Other names
Carbonate of potash, dipotassium carbonate, sub-carbonate of potash, pearl ash, potash, salt of tartar, salt of wormwood.
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.008.665 Edit this at Wikidata
E number E501(i) (acidity regulators, ...)
RTECS number
  • TS7750000
UNII
  • InChI=1S/CH2O3.2K/c2-1(3)4;;/h(H2,2,3,4);;/q;2*+1/p-2 checkY
    Key: BWHMMNNQKKPAPP-UHFFFAOYSA-L checkY
  • InChI=1/CH2O3.2K/c2-1(3)4;;/h(H2,2,3,4);;/q;2*+1/p-2
    Key: BWHMMNNQKKPAPP-NUQVWONBAS
  • C(=O)([O-])[O-].[K+].[K+]
Properties
K
2
CO
3
Molar mass 138.205 g/mol
Appearance White, hygroscopic solid
Density 2.43 g/cm3
Melting point 891 °C (1,636 °F; 1,164 K)
Boiling point Decomposes
110.3 g/100 mL (20 °C)
149.2 g/100 mL (100 °C)
Solubility
−59.0·10−6 cm3/mol
Thermochemistry[1]
114.4 J·mol−1·K−1
155.5 J·mol−1·K−1
−1151.0 kJ·mol−1
−1063.5 kJ·mol−1
Enthalpy of fusion fHfus)
27.6 kJ·mol−1
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H302, H315, H319, H335
P261, P305+P351+P338
NFPA 704 (fire diamond)
1
0
0
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
1870 mg/kg (oral, rat)[2]
Safety data sheet (SDS) ICSC 1588
Related compounds
Other anions
Potassium bicarbonate
Other cations
Lithium carbonate
Sodium carbonate
Rubidium carbonate
Caesium carbonate
Related compounds
Ammonium carbonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Potassium carbonate is the inorganic compound with the formula K2CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass.[3]

History[edit]

Potassium carbonate is the primary component of potash and the more refined pearl ash or salts of tartar. Historically, pearl ash was created by baking potash in a kiln to remove impurities. The fine, white powder remaining was the pearl ash. The first patent issued by the US Patent Office was awarded to Samuel Hopkins in 1790 for an improved method of making potash and pearl ash.

In late 18th-century North America, before the development of baking powder, pearl ash was used as a leavening agent for quick breads.[4][5]

Production[edit]

Potassium carbonate is prepared commercially by the reaction potassium hydroxide with carbon dioxide:[3]

2 KOH + CO2 → K2CO3 + H2O

From the solution crystallizes the sesquihydrate K2CO3·32H2O ("potash hydrate"). Heating this solid above 200 °C (392 °F) gives the anhydrous salt. In an alternative method, potassium chloride is treated with carbon dioxide in the presence of an organic amine to give potassium bicarbonate, which is then calcined:

2 KHCO3 → K2CO3 + H2O + CO2

Applications[edit]

References[edit]

  1. ^ CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data. William M. Haynes, David R. Lide, Thomas J. Bruno (2016-2017, 97th ed.). Boca Raton, Florida. 2016. ISBN 978-1-4987-5428-6. OCLC 930681942.{{cite book}}: CS1 maint: others (link)
  2. ^ Chambers, Michael. "ChemIDplus - 584-08-7 - BWHMMNNQKKPAPP-UHFFFAOYSA-L - Potassium carbonate [USP] - Similar structures search, synonyms, formulas, resource links, and other chemical information". chem.sis.nlm.nih.gov. Archived from the original on 2014-08-12.
  3. ^ a b H. Schultz, G. Bauer, E. Schachl, F. Hagedorn, P. Schmittinger (2005). "Potassium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_039. ISBN 3527306730.{{cite encyclopedia}}: CS1 maint: uses authors parameter (link)
  4. ^ See references to "pearl ash" in "American Cookery" by Amelia Simmons, printed by Hudson & Goodwin, Hartford, 1796.
  5. ^ Civitello, Linda (2017). Baking powder wars : the cutthroat food fight that revolutionized cooking. Urbana, Illinois: University of Illinois Press. pp. 18–22. ISBN 9780252041082.
  6. ^ Leonard, J.; Lygo, B.; Procter, G. "Advanced Practical Organic Chemistry" 1998, Stanley Thomas Publishers Ltd
  7. ^ Child, Lydia M. "The American Frugal Housewife" 1832

Bibliography[edit]

External links[edit]