Names | |
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IUPAC name Potassium carbonate | |
Other names Carbonate of potash, dipotassium carbonate, sub-carbonate of potash, pearl ash, pearlash, 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 | |
K2CO3 | |
Molar mass | 138.205 g·mol−1 |
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·K) |
Std molar entropy (S⦵298) | 155.5 J/(mol·K) |
Std enthalpy of formation (ΔfH⦵298) | −1151.0 kJ/mol |
Gibbs free energy (ΔfG⦵) | −1063.5 kJ/mol |
Enthalpy of fusion (ΔfH⦵fus) | 27.6 kJ/mol |
Hazards | |
GHS labelling: | |
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 | |
Related compounds | |
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 K 2 C O 3. 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] Potassium carbonate is a potassium salt of carbonic acid. This salt consists of potassium cations K+ and carbonate anions CO2−3, and is therefore an alkali metal carbonate.
Potassium carbonate is the primary component of potash and the more refined pearl ash or salt 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. [5]
In late 18th-century North America, before the development of baking powder, pearl ash was used as a leavening agent for quick breads. [6] [7]
The modern commercial production of potassium carbonate is by reaction of potassium hydroxide with carbon dioxide: [3]
From the solution crystallizes the sesquihydrate K2CO3·1.5H2O ("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:
Ash is the solid remnants of fires. Specifically, ash refers to all non-aqueous, non-gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash is the non-gaseous, non-liquid residue after complete combustion.
In inorganic chemistry, bicarbonate is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula HCO−
3.
A carbonate is a salt of carbonic acid,, 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.
Potassium hexacyanidoferrate(II) is the inorganic compound with formula K4[Fe(CN)6]·3H2O. It is the potassium salt of the coordination complex [Fe(CN)6]4−. This salt forms lemon-yellow monoclinic crystals.
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, although it is more commonly found as a component of the mineral trona.
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 chloralkali process.
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.
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.
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.
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.
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.
The Solvay process or ammonia–soda process is the major industrial process for the production of sodium carbonate (soda ash, Na2CO3). The ammonia–soda process was developed into its modern form by the Belgian chemist Ernest Solvay during the 1860s. The ingredients for this are readily available and inexpensive: salt brine (from inland sources or from the sea) and limestone (from quarries). The worldwide production of soda ash in 2005 was estimated at 42 million tonnes, which is more than six kilograms (13 lb) per year for each person on Earth. Solvay-based chemical plants now produce roughly three-quarters of this supply, with the remaining being mined from natural deposits. This method superseded the Leblanc process.
Potassium bitartrate, also known as potassium hydrogen tartrate, with formula KC4H5O6, is a chemical compound with a number of uses. It is the potassium acid salt of tartaric acid (a carboxylic acid). Especially in cooking, it is also known as cream of tartar.
Ammonium carbonate is a chemical compound with the chemical formula [NH4]2CO3. It is an ammonium salt of carbonic acid. It is composed of ammonium cations [NH4]+ and carbonate anions CO2−3. Since ammonium carbonate 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. It comes in the form of a white powder or block, with a molar mass of 96.09 g/mol and a density of 1.50 g/cm3. It is a strong electrolyte.
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.
A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user, or otherwise requires the equipment, personnel, resources or expertise of a fire brigade. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent that can be discharged to extinguish a fire. Fire extinguishers manufactured with non-cylindrical pressure vessels also exist, but are less common.
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.
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