Potassium Carbonate Powder

Cas Number


Other Names

Carbonate of potash,

Dipotassium carbonate,

Sub-carbonate of potash,

Pearl ash,


Salt of tartar,

Salt of wormwood.

The formula



Potassium carbonate (K2CO3) is a white salt, soluble in water (insoluble in ethanol)[2] which forms a strongly alkaline solution. It can be made as the product of potassium hydroxide's absorbent reaction with carbon dioxide. It is deliquescent, often appearing a damp or wet solid. Potassium carbonate is used in the production of soap and glass.

Physical and Chemical Properties
Molar mass 138.20 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
Solubility in water 112 g/100 mL (20 °C), 156 g/100 mL (100 °C)
Solubility 3.11 g/100 mL (25 °C) Methanol, insoluble in alcohol, acetone
Magnetic susceptibility (χ) −59.0·10−6 cm3/mol

historically) for soap, glass, and china production.

as a mild drying agent where other drying agents, such as calcium chloride and magnesium sulfate, may be incompatible. It is not suitable for acidic compounds, but can be useful for drying an organic phase if one has a small amount of acidic impurity. It may also be used to dry some ketones, alcohols, and amines prior to distillation.[4]

in cuisine, where it has many traditional uses. It is an ingredient in the production of grass jelly, a food consumed in Chinese and Southeast Asian cuisines, as well as Chinese noodles and moon cake. It is used to tenderize tripe. German gingerbread recipes often use potassium carbonate as a baking agent, although in combination with hartshorn. It is however important that the right quantities are used to prevent harm, and cooks should not use it without guidance.

in the production of cocoa powder to balance the pH (i.e., reduce the acidity) of natural cocoa beans; it also enhances aroma. The process of adding potassium carbonate to cocoa powder is usually called "Dutching" (and the products referred to as Dutch-processed cocoa powder), as the process was first developed in 1828 by Coenrad Johannes van Houten, a Dutchman.

as a buffering agent in the production of mead or wine.

in antique documents, it is reported to have been used to soften hard water.[5]

as a fire suppressant in extinguishing deep-fat fryers and various other B class-related fires.

in condensed aerosol fire suppression, although as the byproduct of potassium


as an ingredient in welding fluxes, and in the flux coating on arc-welding rods.

as an animal feed ingredient to satisfy the potassium requirements of farmed animals such as broiler breeders.