Potassium bifluoride is the
inorganic compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemis ...
with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...
. This colourless salt consists of the
potassium
Potassium is the chemical element with the symbol K (from Neo-Latin '' kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmos ...
cation
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...
() and the
bifluoride
The bifluoride ion is an inorganic anion with the chemical formula . The anion is colorless. Salts of bifluoride are commonly encountered in the reactions of fluoride salts with hydrofluoric acid. The commercial production of fluorine involves e ...
anion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
(). The salt is used as an
etchant
Etching is a printmaking technique in art.
Etching may also refer to:
* Etching (microfabrication), a process in producing microelectronics
* Glass etching, a glass decoration technique
* Chemical milling, or industrial etching
* Photochemical ma ...
for glass.
Sodium bifluoride
Sodium bifluoride is the inorganic compound with the formula . It is a salt of sodium cation () and bifluoride anion (). It is a white, water-soluble solid that decomposes upon heating . Sodium bifluoride is non-flammable, hygroscopic, and has a ...
is related and is also of commercial use as an etchant as well as in cleaning products.
Synthesis and reactions
The salt was prepared by
Edmond Frémy by treating
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 ...
or
potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash.
Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exp ...
with hydrofluoric acid:
:
With one more equivalent of HF, (CAS#12178-06-2, m.p. 71.7 C) is produced:
:
Thermal decomposition of gives
hydrogen fluoride
Hydrogen fluoride (fluorane) is an inorganic compound with the chemical formula . This colorless gas or liquid is the principal industrial source of fluorine, often as an aqueous solution called hydrofluoric acid. It is an important feedstock ...
:
:
Applications
The industrial production of
fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactiv ...
entails the electrolysis of molten and .
[ The ]electrolysis
In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from n ...
of was first used by Henri Moissan
Ferdinand Frédéric Henri Moissan (28 September 1852 – 20 February 1907) was a French chemist and pharmacist who won the 1906 Nobel Prize in Chemistry for his work in isolating fluorine from its compounds. Moissan was one of the original mem ...
in 1886.
See also
* Ammonium bifluoride
* Bifluoride anion
References
{{fluorine compounds
Inorganic compounds
Potassium compounds
Metal halides
Bifluorides
Alkali metal fluorides