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 a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass.
Carbonate of potash, dipotassium carbonate, sub-carbonate of potash, pearl ash, potash, salt of tartar, salt of wormwood.
3D model (JSmol)
|E number||E501(i) (acidity regulators, ...)|
|Molar mass||138.205 g/mol|
|Appearance||White, hygroscopic solid|
|Melting point||891 °C (1,636 °F; 1,164 K)|
|112 g/100 mL (20 °C) |
156 g/100 mL (100 °C)
|Safety data sheet||ICSC 1588|
|GHS signal word||Warning|
|H302, H315, H319, H335|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|1870 mg/kg (oral, rat)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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.
From the solution crystallizes the sesquihydrate K2CO3.1.5H2O ("potash hydrate"). Heating this solid above 200 °C gives the anhydrous salt. Alternative method, potassium chloride is treated with carbon dioxide in the presence of an organic amine to give potassium bicarbonate, which is then calcined:
In organic chemistry, AD-mix is a commercially available mixture of reagents that acts as an asymmetric catalyst for various chemical reactions, including the Sharpless asymmetric dihydroxylation of alkenes. The two letters AD, stand for asymmetric dihydroxylation. The mix is available in two variations, "AD-mix α" and "AD-mix β" following ingredient lists published by Barry Sharpless.The mixes contain:
Potassium osmate K2OsO2(OH)4 as the source of Osmium tetroxide
Potassium ferricyanide K3Fe(CN)6, which is the re-oxidant in the catalytic cycle
A chiral ligand:
AD-mix α contains (DHQ)2PHAL, the phthalazine adduct with dihydroquinineAD-mix β contains (DHQD)2PHAL, the phthalazine adduct with dihydroquinidineAlkali manufacture
This is a historical article, primarily based on the Encyclopædia Britannica Eleventh Edition. For current information see sodium hydroxide manufacture and Chloralkali process.Alkali manufacture is the process by which an alkali is made. Typical alkalis, produced commercially, include sodium hydroxide, sodium carbonate, potassium hydroxide and potassium carbonate.
A number of processes have been proposed for the manufacture of alkali from various metals, the most common being the Leblanc and ammonia-soda processes.Barilla
Barilla refers to several species of salt-tolerant (halophyte) plants that, until the 19th Century, were the primary source of soda ash and hence of sodium carbonate. The word "barilla" was also used directly to refer to the soda ash obtained from plant sources. The word is an anglicization of the Spanish word barrilla for saltwort plants (a particular category of halophytes).
A very early reference indicating the value placed upon soda ash in Catalonia has been given by Glick, who notes that "In 1189 the monastery of Poblet granted to the glassblower Guillem the right to gather glasswort in return for tithe and two hundred pounds of sheet glass paid annually (The site of these glassworks, at Narola, was excavated in 1935.)." By the 18th Century, Spain's barilla industry was exporting large quantities of soda ash of exceptional purity; the product was refined from the ashes of barilla plants that were specifically cultivated for this purpose. Presumably the word "barilla" entered English and other languages as a consequence of this export trade. The main Spanish barilla species included (i) Salsola soda (the common English term barilla plant for Salsola soda reflects this usage), (ii) Salsola kali, and (iii) Halogeton sativus (formerly Salsola sativa). Fairly recently, Pérez has concluded that the most prominent species was likely Halogeton sativus; earlier authors have tended to favor Salsola soda.
The word "barilla" was also used directly to refer to soda ash from any plant source, including not only the saltworts grown in Spain, but also glassworts, mangroves, and seaweed. These types of plant-derived soda ash are impure alkali substances that contain widely varying amounts of sodium carbonate (Na2CO3), some additional potassium carbonate (also an alkali), and a predominance of non-alkali impurities. The sodium carbonate, which is water-soluble, is "lixiviated" (extracted with water) from the ashes of the burned, dried plants. The resulting solution is boiled dry to obtain the finished barilla. A very similar process is used to obtain potash (mainly potassium carbonate) from the ashes of hardwood trees. The best Spanish barilla—prepared by master barrilleros—contained about 30% Na2CO3. In 1877 Kingzett described the importance of the barilla trade to Spain as follows: "So highly was the product valued, and the importance of the trade regarded, that by the laws of Spain the exportation of the seed was an offence punishable by death."Some authors indicate that "barilla" was a specific plant used for soda ash production; this usage is erroneous, but presumably corresponds to the common usage of "barilla plant" exclusively for Salsola soda. Perhaps this common usage itself reflects an old error in assuming that a single plant species was used by the Spaniards for their industry. In still earlier times, the sources of soda ash and the methods of processing it were secrets that were zealously guarded.Cannizzaro reaction
The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction that involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to give a primary alcohol and a carboxylic acid.
Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium hydroxide or potassium hydroxide, giving the sodium or potassium carboxylate salt of the carboxylic-acid product:
2 C6H5CHO + KOH → C6H5CH2OH + C6H5COOKThe process is a redox reaction involving transfer of a hydride from one substrate molecule to the other: one aldehyde is oxidized to form the acid, the other is reduced to form the alcohol.Carbonate
In chemistry, a carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula of CO2−3. The name may also refer to a carbonate ester, an organic compound containing the carbonate group C(=O)(O–)2.
The term is also used as a verb, to describe carbonation: the process of raising the concentrations of carbonate and bicarbonate ions in water to produce carbonated water and other carbonated beverages – either by the addition of carbon dioxide gas under pressure, or by dissolving carbonate or bicarbonate salts into the water.
In geology and mineralogy, the term "carbonate" can refer both to carbonate minerals and carbonate rock (which is made of chiefly carbonate minerals), and both are dominated by the carbonate ion, CO2−3. Carbonate minerals are extremely varied and ubiquitous in chemically precipitated sedimentary rock. The most common are calcite or calcium carbonate, CaCO3, the chief constituent of limestone (as well as the main component of mollusc shells and coral skeletons); dolomite, a calcium-magnesium carbonate CaMg(CO3)2; and siderite, or iron(II) carbonate, FeCO3, an important iron ore. Sodium carbonate ("soda" or "natron") and potassium carbonate ("potash") have been used since antiquity for cleaning and preservation, as well as for the manufacture of glass. Carbonates are widely used in industry, e.g. in iron smelting, as a raw material for Portland cement and lime manufacture, in the composition of ceramic glazes, and more.Hot potassium carbonate
Hot potassium carbonate, HPC, is a method used to remove carbon dioxide from gas mixtures, also referred to as carbon scrubbing. The inorganic compound potassium carbonate is mixed with a gas mixture and the liquid absorbs carbon dioxide through chemical processes. The technology is a post-combustion capture process and is a form of chemical absorption.HPC can be used for carbon capture and storage as well as carbon capture and utilization. The technology is planned to be used on full scale on a heat plant in Stockholm from 2025.Kaliapparat
A kaliapparat is a laboratory device invented in 1831 by Justus von Liebig (1803–1873) for the analysis of carbon in organic compounds. The device, made of glass, consists of a series of five bulbs connected and arranged in a triangular shape.
To determine the carbon in an organic compound with a kaliapparat, the substance is first burned, converting any carbon present into carbon dioxide (CO2). The vaporous products are passed through the kaliapparat, which is filled with potassium hydroxide (KOH) solution. The potassium hydroxide reacts with the CO2 to make potassium carbonate. The reaction, ignoring ionic dissociation, can be written as follows:
2 KOH + CO2 → K2CO3 + H2O.
Subtracting the mass of the kaliapparat before the combustion from that found after the combustion gives the amount of CO2 absorbed. From the mass of CO2 thus found, standard stoichiometric calculations then give the mass of carbon in the original sample.
A stylized symbol of a kaliapparat is used in the American Chemical Society logo, originally designed in the early 20th century by Tiffany's Jewelers.Kermes mineral
Kermes mineral or Alkermes mineral was a compound of antimony oxides and sulfides, more specifically, antimony trioxide and trisulfide. It can be made or obtained in the laboratory by the actions of potassium carbonate (K2CO3) on antimony sulfide. The compound is reddish brown in color and described as a velvety powder which is insoluble in water. It was used extensively in the medical field until the general use of antimony compounds declined due to toxic effects.List of alchemical substances
Alchemical studies produced a number of substances, which were later classified as particular chemical compounds or mixtures of compounds.
Many of these terms were in common use into the 20th century.
Aqua Fortis – nitric acid, formed by 2 parts saltpetre in 1 part (pure) oil of vitriol (sulfuric acid). (Historically, this process could not have been used, as 98% oil of vitriol was not available.)
Aqua Ragia/Spirit of turpentine/Oil of turpentine/Gum turpentine – turpentine, formed by the distillation of pine tree resin
Aqua Regia (Latin: "royal water") – a mixture of aqua fortis and spirit of salt
Aqua Tofani – arsenic trioxide, As2O3 (extremely poisonous)
Aqua vitae/Spirit of Wine – ethanol, formed by distilling wine
Azoth - initially this referred to a supposed universal solvent but later became another name for Mercury
Bismuth (German: Wismuth)
Bitumen - highly viscous liquid or semi-solid form of petroleum
Blue Vitriol/Bluestone – A mineral; copper(II) sulfate pentahydrate.
Brimstone – sulfurFlowers of sulfur – formed by distilling sulfur.Butter (or oil) of antimony – antimony trichloride. Formed by distilling roasted stibnite with corrosive sublimate, or dissolving stibnite in hot concentrated hydrochloric acid and distilling. SbCl3
Cadmia/Tuttia/Tutty – probably zinc carbonate
Calamine – zinc carbonate
Calomel/Horn Quicksilver/horn mercury – mercury(I) chloride, a very poisonous purgative formed by subliming a mixture of mercuric chloride and metallic mercury, triturated in a mortar and heated in an iron pot. The crust formed on the lid was ground to powder and boiled with water to remove the calomel.
Caustic potash/Caustic Wood Alkali – potassium hydroxide, formed by adding lime to potash
Caustic Soda/Caustic Marine Alkali – sodium hydroxide, NaOH, formed by adding lime to natron
Caustic Volatile Alkali – ammonium hydroxide
Chalk – a rock composed of porous biogenic calcium carbonate, CaCO3
Chrome green – chromic oxide and cobalt oxide
Chrome orange – chrome yellow and chrome red
Chrome red – basic lead chromate – PbCrO4+PbO
Chrome yellow/Paris Yellow/Leipzig Yellow – lead chromate, PbCrO4
Cinnabar/Vermilion – refers to several substances, among them: mercury(II) sulfide (HgS), or native vermilion (the common ore of mercury).
Copper Glance – copper(I) sulfide ore.
Corrosive sublimate – mercuric chloride, formed by subliming mercury, calcined green vitriol, common salt, and nitre
Cuprite – copper(I) oxide ore
Dutch White – a pigment, formed from one part of white lead to three of barium sulfate, BaSO4
Flowers of antimony – antimony trioxide, formed by roasting stibnite at high temperature and condensing the white fumes that form. SbO3
Fool's gold – a mineral, iron disulfide or pyrite; can form oil of vitriol on contact with water and air.
Fulminating silver – silver nitride, formed by dissolving silver(I) oxide in ammonia. Very explosive when dry.
Fulminating gold – gold hydrazide, formed by adding ammonia to the auric hydroxide. When dry, can explode on concussion.
Fulminating gold – unstable gold carbonate formed by precipitation by potash from gold dissolved in aqua regia
Galena – lead(II) sulfide. Lead ore.
Glass of antimony – impure antimony tetroxide, SbO4 formed by roasting stibnite. A yellow pigment for glass and porcelain.
Glauber's Salt – sodium sulfate. Na2SO4
Green Vitriol – a mineral; iron(II) sulfate heptahydrate. (or ferrous sulfate)Marcasite – a mineral; iron disulfide. In moist air it turns into green vitriol, FeSO4.
Rouge/Crocus/Colcothar – ferric oxide, formed by burning green vitriol in airGum Arabic – gum from the acacia tree
Gypsum – a mineral; calcium sulfate, CaSO4
Horn Silver/Argentum Cornu – a weathered form of chlorargyrite, an ore of silver chlorideLuna cornea – silver chloride, formed by heating horn silver till it liquefies and then coolingKing's yellow – formed by mixing orpiment with white arsenic
Lapis solaris (Bologna stone) – barium sulfide – 1603, Vincenzo Cascariolo
Lead fume – lead oxide, found in flues at lead smelters
Lime/Quicklime (Burnt Lime)/Calx Viva/Unslaked Lime – calcium oxide, formed by calcining limestoneSlaked Lime – calcium hydroxide, Ca(OH)2Liver of sulfur – formed by fusing potash and sulfur
Lunar caustic/lapis infernalis – silver nitrate, formed by dissolving silver in aqua fortis and evaporating
Lye – potash in a water solution, formed by leaching wood ashesPotash/Salt of tartar – potassium carbonate, formed by evaporating lye. K2CO3
Pearlash – formed by baking potash in a kilnMassicot – lead monoxide, PbOLitharge – lead monoxide, formed by fusing and powdering massicot
Minium/Red Lead – trilead tetroxide, Pb3O4; formed by roasting litharge in air
Naples yellow/Cassel yellow – oxychloride of lead, formed by heating litharge with sal ammoniacMercurius praecipitatus – red mercuric oxide
Milk of Sulfur (lac sulphuris) – formed by adding an acid to thion hudor (lime sulfur)
Mosaic gold – stannic sulfide, formed by heating a mixture of tin filings, sulfur, and sal-ammoniac
Natron/Soda Ash/Soda – sodium carbonate, Na2CO3
Nitrum Flammans – ammonium nitrate
Oil of Tartar – concentrated potassium carbonate, K2CO3 solution
Oil of Tartar per Deliquium – potassium carbonate dissolved in the water which its extracts from the air
Oil of Vitriol/Spirit of Vitriol – sulfuric acid, a weak version can be formed by heating green vitriol and blue vitriol. H2SO4
Orpiment – arsenic trisulfide, an ore of arsenic
Pearl white – bismuth nitrate, BiNO3
Philosophers' Wool/nix alba (white snow)/Zinc White – zinc oxide, formed by burning zinc in air, used as a pigment
Plumbago – a mineral, graphite; not discovered in pure form until 1564
Powder of Algaroth – antimonious oxychloride, formed by precipitation when a solution of butter of antimony and spirit of salt is poured into water
Purple of Cassius – formed by precipitating a mixture of gold, stannous and stannic chlorides, with alkali. Used for glass coloring
Quicksilver - Mercury
Realgar – arsenic disulfide, an ore of arsenic
Red Vitriol - cobalt sulfate
Regulus of antimony
Resin of copper – copper(I) chloride (cuprous chloride), formed by heating copper with corrosive sublimate
Sal Ammoniac – ammonium chloride
Sal Petrae (Med. Latin: "stone salt")/Salt of Petra/Saltpetre/Nitrate of potash – potassium nitrate, KNO3, typically mined from covered dungheaps
Salt/Common salt – A mineral; sodium chloride, NaCl, formed by evaporating seawater (impure form)
Salt of Hartshorn/Sal Volatile – ammonium carbonate formed by distilling bones and horns
Spirit of box/Pyroxylic spirit – methanol, CH3OH, distilled wood alcohol
Spirit of Hartshorn – ammonia, formed by the decomposition of sal-ammoniac by unslaked lime
Spirit of Salt/Acidum Salis – the liquid form of hydrochloric acid (also called muriatic acid), formed by mixing common salt with oil of vitriolMarine Acid Air – gaseous form of hydrochloric acidSpiritus fumans – stannic chloride, formed by distilling tin with corrosive sublimateTin salt – hydrated stannous chloride
Butter of tin – hydrated tin(IV) chlorideStibnite – antimony or antimony trisulfide, ore of antimony
Sugar of Lead – lead(II) acetate, formed by dissolving lead oxide in vinegar
Sweet Vitriol – diethyl ether. It could be made by mixing oil of vitriol with spirit of wine and heating it.
Thion Hudor – lime sulfur, formed by boiling flowers of sulfur with slaked lime
Turpeth mineral – hydrolysed form of mercury(II) sulfate
Verdigris – Carbonate of Copper or (more recently) copper(II) acetate. The carbonate is formed by weathering copper. The acetate is formed by vinegar acting on copper. One version was used as a green pigment.
White arsenic – arsenious oxide, formed by subliminating arsenical soot from the roasting ovens
White lead – carbonate of lead, a toxic pigment, produced by corroding stacks of lead plates with dilute vinegar beneath a heap of moistened wood shavings. (replaced by blanc fixe & lithopone)
White vitriol – zinc sulfate, formed by lixiviating roasted zinc blende
Venetian White – formed from equal parts of white lead and barium sulfate
Zaffre – impure cobalt arsenate, formed after roasting cobalt ore
Zinc Blende – zinc sulfideList of desiccants
A desiccant is a substance that absorbs water. It is most commonly used to remove humidity that would normally degrade or even destroy products sensitive to moisture.
List of desiccants:
Calcium sulfate (Drierite)
Abu Mansur Muvaffak Harawi (Persian: ابو منصور موفق هروی) was a 10th-century Persian physician.
He flourished in Herat (modern-day Afghanistan), under the Samanid prince Mansur I, who ruled from 961 to 976.
He was apparently the first to think of compiling a treatise on materia medica in Persian; he travelled extensively in Persia and India to obtain the necessary information.
Abu Mansur distinguished between sodium carbonate and potassium carbonate, and seems to have had some knowledge about arsenious oxide, cupric oxide, silicic acid, and antimony; he knew the toxicological effects of copper and lead compounds, the depilatory vertue of quicklime, the composition of plaster of Paris and its surgical use.Orcein
Orcein, also archil, orchil, lacmus and C.I. Natural Red 28, are names for dyes extracted from several species of lichen, commonly known as "orchella weeds", found in various parts of the world. A major source is the archil lichen, Roccella tinctoria. Orcinol is extracted from such lichens. It is then converted to orcein by ammonia and air. In traditional dye-making methods, urine was used as the ammonia source. If the conversion is carried out in the presence of potassium carbonate, calcium hydroxide, and calcium sulfate (in the form of potash, lime, and gypsum in traditional dye-making methods), the result is litmus, a more complex molecule. The manufacture was described by Cocq in 1812 and in the UK in 1874. Edmund Roberts noted orchilla as a principal export of the Cape Verde islands, superior to the same kind of moss found in Italy or the Canary Islands, that in 1832 was yielding an annual revenue of $200,000. Commercial archil is either a powder (called cudbear) or a paste. It is red in acidic pH and blue in alkaline pH.Peroxydicarbonate
In chemistry, peroxydicarbonate (sometimes peroxodicarbonate) is a divalent anion with formula C2O2−6. It is one of the oxocarbon anions, which consist solely of carbon and oxygen. Its molecular structure can be viewed as two carbonate anions joined so as to form a peroxide bridge –O–O–.
The anion is formed, together with peroxocarbonate CO2−4, at the negative electrode during electrolysis of molten lithium carbonate. The anion can also be obtained by electrolysis of a saturated solution of rubidium carbonate in water.Potassium peroxydicarbonate K2C2O6 was obtained by Constam and von Hansen in 1895; its crystal structure was determined only in 2002. It too can be obtained by electrolysis of a saturated potassium carbonate solution at −20 °C. It is a light blue crystalline solid that decomposes at 141 °C, releasing oxygen and carbon dioxide, and decomposes slowly at lower temperatures.Rubidium peroxodicarbonate is a light blue crystalline solid that decomposes at 424 K (151 °C). Its structure was published in 2003. In both salts, each of the two carbonate units is planar. In the rubidium salt the whole molecule is planar, whereas in the potassium salt the two units lie on different and nearly perpendicular planes, both of which contain the O–O bond.Potash
Potash () includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, which refers to plant ashes soaked in water in a pot, the primary means of manufacturing the product before the industrial era. The word potassium is derived from potash.Potash is produced worldwide at amounts exceeding 90 million tonnes (40 million tonnes K2O equivalent) per year, mostly for use in manufacturing. Various types of fertilizer-potash constitute the single largest industrial use of the element potassium in the world. Potassium was first derived in 1807 by electrolysis of caustic potash (potassium hydroxide).Potash (disambiguation)
Potash may refer to:
Potash, potassium carbonate
Potash, Suffolk, United Kingdom
Potash City, Jordan
Potash Corporation of Saskatchewan
Potashes (gang), a 19th-century New York City street gangPotash pit
Potash pits were kiln sites which were dug and lined with drystone walling for the production of potash prior to the Industrial Revolution. The scouring or degreasing of the natural lanolin from wool requires the application of soft soap produced using fat and an alkaline potash solutionthat contains water-soluble potassium salts such as potassium carbonate and potassium hydroxide.Potassium bicarbonate
Potassium bicarbonate (also known as potassium hydrogen carbonate or potassium acid carbonate) is the inorganic compound with the chemical formula KHCO3. It is a white solid.Saang mein
Saang mein is a type of Chinese noodle found in Hong Kong. It is often available in overseas Chinatowns.