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 OOjs UI icon edit-ltr-progressive.svg
E number E501(i) (acidity regulators, ...)
PubChem CID
RTECS number
  • TS7750000
UNII
  • InChI=1S/CH2O3.2K/c2-1(3)4;;/h(H2,2,3,4);;/q;2*+1/p-2 Yes check.svgY
    Key: BWHMMNNQKKPAPP-UHFFFAOYSA-L Yes check.svgY
  • 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
AppearanceWhite, hygroscopic solid
Density 2.43 g/cm3
Melting point 891 °C (1,636 °F; 1,164 K)
Boiling point Decomposes
110.3 g/100mL (20 °C)
149.2 g/100mL (100 °C)
Solubility
Acidity (pKa)10.25
−59.0·10−6 cm3/mol
Thermochemistry [1]
114.4 J·mol−1·K−1
Std molar
entropy
(S298)
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:
GHS-pictogram-exclam.svg
Warning
H302, H315, H319, H335
P261, P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704.svgHealth 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
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).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Potassium carbonate is the inorganic compound with the formula K2 CO3. It is a white salt, which is soluble in water and forms a strongly alkaline solution. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass. [3] Commonly, it can be found as the result of leakage of alkaline batteries. [4]

Contents

History

Potassium carbonate is the primary component of potash and the more refined pearl ash or salts of tartar. 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. [5] [6]

In late 18th-century North America, before the development of baking powder, pearl ash was used as a leavening agent for quick breads. [7] [8]

Production

Potassium lye (which in this case can alternatively be called potash), a substance which contains potassium carbonate, potassium bicarbonate, and potassium hydroxide, [9] [10] was historically produced by dissolving the lye found in the wooden ashes inside of water for at least 24 hours, disposing of the undissolved ashes, and then drying/evaporating the remaining liquid. [9] [11]

With modern observation, this process would produce greater yields if done with the ashes of banana peels due to their increased amounts of potassium carbonate. [11]

As previously mentioned, Samuel Hopkins created an improved method of making pearl ash. One of those procedures was putting the lye/potash in a kiln to remove impurities.

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

2 KOH + CO2 → K2CO3 + H2O

From the solution crystallizes the sequestrate 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

Related Research Articles

In chemistry, an alkali is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases.

<span class="mw-page-title-main">Carbonate</span> Salt or ester of carbonic acid

A carbonate is a salt of carbonic acid, H2CO3, characterized by the presence of the carbonate ion, a polyatomic ion with the formula CO2−3. The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate groupO=C(−O−)2.

<span class="mw-page-title-main">Potash</span> Salt mixture

Potash includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, plant ashes or wood ash soaked in water in a pot, the primary means of manufacturing potash before the Industrial Era. The word potassium is derived from potash.

<span class="mw-page-title-main">Sodium hydroxide</span> Chemical compound with formula NaOH

Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH.

<span class="mw-page-title-main">Sodium bicarbonate</span> Chemical compound

Sodium bicarbonate (IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation (Na+) and a bicarbonate anion (HCO3). Sodium bicarbonate is a white solid that is crystalline, but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite. It is a component of the mineral natron and is found dissolved in many mineral springs.

<span class="mw-page-title-main">Sodium carbonate</span> Chemical compound

Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the Chlor-alkali process.

<span class="mw-page-title-main">Baking powder</span> Dry chemical leavening agent

Baking powder is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate and a weak acid. The base and acid are prevented from reacting prematurely by the inclusion of a buffer such as cornstarch. Baking powder is used to increase the volume and lighten the texture of baked goods. It works by releasing carbon dioxide gas into a batter or dough through an acid–base reaction, causing bubbles in the wet mixture to expand and thus leavening the mixture. The first single-acting baking powder was developed by food manufacturer Alfred Bird in England in 1843. The first double-acting baking powder, which releases some carbon dioxide when dampened and later releases more of the gas when heated by baking, was developed by Eben Norton Horsford in the U.S. in the 1860s.

In cooking, a leavening agent or raising agent, also called a leaven or leavener, is any one of a number of substances used in doughs and batters that cause a foaming action that lightens and softens the mixture. An alternative or supplement to leavening agents is mechanical action by which air is incorporated. Leavening agents can be biological or synthetic chemical compounds. The gas produced is often carbon dioxide, or occasionally hydrogen.

<span class="mw-page-title-main">Potassium hydroxide</span> Inorganic compound (KOH)

Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.

<span class="mw-page-title-main">Potassium bicarbonate</span> Chemical compound

Potassium bicarbonate (IUPAC name: potassium hydrogencarbonate, also known as potassium acid carbonate) is the inorganic compound with the chemical formula KHCO3. It is a white solid.

<span class="mw-page-title-main">Ammonium bicarbonate</span> Chemical compound

Ammonium bicarbonate is an inorganic compound with formula (NH4)HCO3. The compound has many names, reflecting its long history. Chemically speaking, it is the bicarbonate salt of the ammonium ion. It is a colourless solid that degrades readily to carbon dioxide, water and ammonia.

<span class="mw-page-title-main">Dutch process cocoa</span> Cocoa that has been treated with an alkalizing agent

Dutch processed cocoa, Dutch cocoa, or alkalized cocoa, is cocoa solids that have been treated with an alkalizing agent to reduce the natural acidity of cocoa, giving it a less bitter taste compared to "natural cocoa" extracted with the Broma process. It forms the basis for much of modern chocolate, and is used in ice cream, hot chocolate, and baking.

The Leblanc process was an early industrial process for making soda ash used throughout the 19th century, named after its inventor, Nicolas Leblanc. It involved two stages: making sodium sulfate from sodium chloride, followed by reacting the sodium sulfate with coal and calcium carbonate to make sodium carbonate. The process gradually became obsolete after the development of the Solvay process.

An ashery is a factory that converts hardwood ashes into lye, potash, or pearlash. Asheries were common in newly settled areas of North America during the late 18th century and much of the 19th century, when excess wood was available as settlers cleared their land for farming. Hardwood ashes contain abundant levels of potassium carbonate and potassium hydroxide, the principal components of the products being produced.

In analytical chemistry, ashing or ash content determination is the process of mineralization for preconcentration of trace substances prior to a chemical analysis, such as chromatography, or optical analysis, such as spectroscopy.

<span class="mw-page-title-main">Cocoa solids</span> Mixture remaining after cocoa butter is extracted from cocoa beans

Dry cocoa solids are the components of cocoa beans remaining after cocoa butter, the fatty component of the bean, is extracted from chocolate liquor, roasted cocoa beans that have been ground into a liquid state. Cocoa butter is 46% to 57% of the weight of cocoa beans and gives chocolate its characteristic melting properties. Cocoa powder is the powdered form of the dry solids with a small remaining amount of cocoa butter. Untreated cocoa powder is bitter and acidic. Dutch process cocoa has been treated with an alkali to neutralize the acid.

<span class="mw-page-title-main">Cleaning agent</span> Substance used to remove dirt or other contaminants

Cleaning agents or hard-surface cleaners are substances used to remove dirt, including dust, stains, foul odors, and clutter on surfaces. Purposes of cleaning agents include health, beauty, removing offensive odor, and avoiding the spread of dirt and contaminants to oneself and others. Some cleaning agents can kill bacteria and clean at the same time. Others, called degreasers, contain organic solvents to help dissolve oils and fats.

<span class="mw-page-title-main">Wood ash</span> Residue powder left after the combustion of wood

Wood ash is the powdery residue remaining after the combustion of wood, such as burning wood in a fireplace, bonfire, or an industrial power plant. It is largely composed of calcium compounds along with other non-combustible trace elements present in the wood. It has been used for many purposes throughout history.

<span class="mw-page-title-main">Condensed aerosol fire suppression</span> Particle-based form of fire extinction

Condensed aerosol fire suppression is a particle-based method of fire extinction. It is similar to but not identical to dry chemical fire extinction methods, using an innovative pyrogenic, condensed aerosol fire suppressant. It is a highly effective fire suppression method for class A, B, C, E and F. Some aerosol-generating compounds produce a corrosive by-product that may damage electronic equipment, although later generations lower the effect.

References

  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: location missing publisher (link) 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. 1 2 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   3-527-30673-0.
  4. List, Jenny (October 19, 2022). "Crusty Leaking Cells Kill Your Tech. Just What's Going On?". Hackaday. Archived from the original on May 30, 2023.
  5. "Milestones in U.S. patenting". www.uspto.gov. Retrieved 2023-08-04.
  6. "Samuel Hopkins (inventor)", Wikipedia, 2023-04-09, retrieved 2023-08-04
  7. See references to "pearl ash" in "American Cookery" by Amelia Simmons, printed by Hudson & Goodwin, Hartford, 1796.
  8. Civitello, Linda (2017). Baking powder wars: the cutthroat food fight that revolutionized cooking. Urbana, Illinois: University of Illinois Press. pp. 18–22. ISBN   978-0-252-04108-2.
  9. 1 2 "Potassium carbonate - Sciencemadness Wiki". www.sciencemadness.org. Retrieved 2023-09-08.
  10. "Lye", Wikipedia, 2023-08-08, retrieved 2023-09-08
  11. 1 2 Smith, Jess (24 April 2017). "How to Make Potassium Carbonate". sciencing.com. Retrieved 3 August 2023.
  12. Leonard, J.; Lygo, B.; Procter, G. "Advanced Practical Organic Chemistry" 1998, Stanley Thomas Publishers Ltd
  13. Child, Lydia M. "The American Frugal Housewife" 1832

Bibliography