Potassium bicarbonate (

IUPAC name In chemical nomenclature, a preferred IUPAC name (PIN) is a unique name, assigned to a chemical substance and preferred among the possible names generated by IUPAC nomenclature. The "preferred IUPAC nomenclature" provides a set of rules for choo ...

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

Production and reactivity

It is manufactured by treating an aqueous solution of

potassium carbonate Potassium carbonate is the inorganic compound with the formula K2 CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used in the production of soap and gl ...

with

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

: :K₂CO₃ + CO₂ + H₂O → 2 KHCO₃ Decomposition of the bicarbonate occurs between : :2 KHCO₃ → K₂CO₃ + CO₂ + H₂O This reaction is employed to prepare high purity potassium carbonate.

Uses

Food and drink

This compound is a source of

for

leavening 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 (gas bubbles) that lightens and softens the mixture. An altern ...

in baking. It can substitute for

baking soda 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) for those with a low-sodium diet, and it is an ingredient in low-sodium

baking powder 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 increas ...

s. As an inexpensive, nontoxic base, it is widely used in diverse application to regulate pH or as a reagent. Examples include as

buffering agent A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is ...

in medications, an additive in

winemaking Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. The science of wine and ...

. Potassium bicarbonate is often found added to

club soda Club soda is a manufactured form of carbonated water, commonly used as a drink mixer. Sodium bicarbonate, potassium sulfate, potassium bicarbonate, potassium citrate, or sodium citrate is artificially added to replicate constituents commonly fo ...

to improve taste, and to soften the effect of effervescence.

Fire extinguishers

Potassium bicarbonate is used as a fire suppression agent ("BC dry chemical") in some dry chemical

fire extinguisher 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 ha ...

s, as the principal component of the Purple-K dry chemical, and in some applications of

condensed aerosol fire suppression Condensed aerosol fire suppression is a particle-based form of fire extinction. It is similar to dry chemical fire extinction). It employs a fire-extinguishing agent consisting of: very fine solid particles as well as gaseous matter. The cond ...

. It is the only dry chemical fire suppression agent recognized by the U.S. National Fire Protection Association for firefighting at airport crash rescue sites. It is about twice as effective in fire suppression as sodium bicarbonate.

Agriculture

Potassium bicarbonate has widespread use in crops, especially for

neutralizing A neutralizing antibody (NAb) is an antibody that defends a cell from a pathogen or infectious particle by neutralizing any effect it has biologically. Neutralization renders the particle no longer infectious or pathogenic. Neutralizing antibod ...

acidic soil Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the n ...

. Potassium bicarbonate is an effective fungicide against

powdery mildew Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of ascomycete fungi in the order Erysiphales. Powdery mildew is one of the easier plant diseases to identify, a ...

and

apple scab Apple scab is a common disease of plants in the rose family (Rosaceae) that is caused by the ascomycete fungus ''Venturia inaequalis''. While this disease affects several plant genera, including ''Sorbus, Cotoneaster,'' and ''Pyrus'', it is mos ...

, allowed for use in

organic farming Organic farming, also known as ecological farming or biological farming,Labelling, article 30 o''Regulation (EU) 2018/848 of the European Parliament and of the Council of 30 May 2018 on organic production and labelling of organic products and re ...

. Potassium bicarbonate is a contact killer for

Spanish moss Spanish moss (''Tillandsia usneoides'') is an epiphytic flowering plant that often grows upon large trees in tropical and subtropical climates. It is native to much of Mexico, Bermuda, the Bahamas, Central America, South America, the Southern Un ...

when mixed 1/4 cup per gallon.

History

The word ''saleratus'', from

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''sal æratus'' meaning "aerated salt", first used in the nineteenth century, refers to both potassium bicarbonate and sodium bicarbonate.

References

External links

Potassium Bicarbonate Handbook

OMRI Potassium Bicarbonate

Safety Data sheet - potassium bicarbonate
* {{Authority control Potassium compounds Acid salts Fire suppression agents