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Names | |
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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 |
E number | E501(i) (acidity regulators, ...) |
PubChem CID | |
RTECS number |
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UNII |
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CompTox Dashboard (EPA) | |
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Properties | |
K 2CO 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 | |
Acidity (pKa) | 10.25 |
−59.0·10−6 cm3/mol | |
Thermochemistry [1] | |
Heat capacity (C) | 114.4 J·mol−1·K−1 |
Std molar entropy (S⦵298) | 155.5 J·mol−1·K−1 |
Std enthalpy of formation (ΔfH⦵298) | −1151.0 kJ·mol−1 |
Gibbs free energy (ΔfG⦵) | −1063.5 kJ·mol−1 |
Enthalpy of fusion (ΔfH⦵fus) | 27.6 kJ·mol−1 |
Hazards | |
GHS labelling: | |
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Warning | |
H302, H315, H319, H335 | |
P261, P305+P351+P338 | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 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). |
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]
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]
Potassium carbonate is prepared commercially by the reaction of potassium hydroxide with carbon dioxide: [3]
From the solution crystallizes the sesquihydrate K2CO3·3⁄2H2O ("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:
Potassium is the chemical element with the symbol K and atomic number 19. It is a silvery-white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge. In nature, potassium occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac-colored flame. It is found dissolved in seawater, and occurs in many minerals such as orthoclase, a common constituent of granites and other igneous rocks.
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23Na. The free metal does not occur in nature, and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans.
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions.
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.
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.
Sodium carbonate refers to a family of inorganic compounds with the formula Na2CO3(H2O)x, where x can range from 0 to 10. 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. 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.
Potassium chloride is a metal halide salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water, and its solutions have a salt-like taste. Potassium chloride can be obtained from ancient dried lake deposits. KCl is used as a fertilizer, in medicine, in scientific applications, domestic water softeners, and in food processing, where it may be known as E number additive E508.
Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.
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.
In metallurgy, a flux is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining.
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.
Potassium bitartrate, also known as potassium hydrogen tartrate, with formula KC4H5O6, is a byproduct of winemaking. In cooking, it is known as cream of tartar. It is processed from the potassium acid salt of tartaric acid (a carboxylic acid). The resulting powdery base can be used in baking or as a cleaning solution (when mixed with an acidic solution such as lemon juice or white vinegar).
Sodium sulfate (also known as sodium sulphate or sulfate of soda) is the inorganic compound with formula Na2SO4 as well as several related hydrates. All forms are white solids that are highly soluble in water. With an annual production of 6 million tonnes, the decahydrate is a major commodity chemical product. It is mainly used as a filler in the manufacture of powdered home laundry detergents and in the Kraft process of paper pulping for making highly alkaline sulfides.
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.
Ammonium carbonate is a salt with the chemical formula (NH4)2CO3. Since it readily degrades to gaseous ammonia and carbon dioxide upon heating, it is used as a leavening agent and also as smelling salt. It is also known as baker's ammonia and is a predecessor to the more modern leavening agents baking soda and baking powder. It is a component of what was formerly known as sal volatile and salt of hartshorn, and produces a pungent smell when baked.
Xanthate usually refers to a salt with the formula ROCS−
2M+
(R = alkyl; M+ = Na+, K+), thus they are the metal-thioate/O-esters of dithiocarbonate. The name xanthates is derived from Ancient Greek ξανθός xanthos, meaning “yellowish, golden”, and indeed most xanthate salts are yellow. They were discovered and named in 1823 by Danish chemist William Christopher Zeise. These organosulfur compounds are important in two areas: the production of cellophane and related polymers from cellulose and (in mining) for extraction of certain ores. They are also versatile intermediates in organic synthesis. Xanthate can also refer to the O,S-ester of xanthic acid. These esters have the structure ROC(=S)SR′.
Phthalimide is the organic compound with the formula C6H4(CO)2NH. It is the imide derivative of phthalic anhydride. It is a sublimable white solid that is slightly soluble in water but more so upon addition of base. It is used as a precursor to other organic compounds as a masked source of ammonia.
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.
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