Potassium fluoride, KF, is a colorless, deliquescent crystalline solid that has a melting point of 846 °C(1550 °F). Potassium fluoride has a salty taste and is poisonous. It is soluble in water,but insoluble in alcohol. Potassium fluoride is used in etching glass,preservatives, and insecticides.
Potassium fluoride is basis raw material of manufacturing fluoride, chemical formula is KF. Molecular weight is 58.10. It is colorless cubic crystal or white powder. It is poisonous! It is deliquescent. Taste is salty. Specific gravity is 2.48. Melting point is 858℃. Boiling point is 1505℃. It is soluble in water. It was dissolved in hydrofluoric acid and ammonia. It is insoluble in ethanol, acetone. Aqueous solution is alkaline and it can corrode glass and porcelain. It can cause irritation for human skin, mucous membrane and eye. When belows 40.2℃, it can crystallize in an aqueous solution to give dihydrate KF·2H2O, which is monoclinic, it is self-dissolved crystalline water at 41℃. It can be obtained by the thermal decomposition of potassium hydrogen fluoride or potassium carbonate (or potassium hydroxide) and hydrofluoric acid (40% or anhydrous). It can be used for glass engraving, food preservation, it can be also used as welding flux, fluoride, pesticides,etc.
Figure 1 the structural formula of potassium fluoride.
Anhydrous Potassium fluoride is used in organic synthesis as a catalyst for various reactions, or to introduce fluorine into organic molecules. For example, fluoro compounds can be prepared by replacing labile chlorine atoms by fluorine atoms, as in the manufacture of sodium fluoroacetate, a rat poison. The nucleophilic strength of F− and the solubility of KF in aprotic organic solvents may be improved by using crown ethers. The “naked” fluoride ion obtained is an efficient fluorinating agent.
Potassium fluoride is prepared by reacting potassium carbonate (or KOH) with aqueous hydrofluoric acid. Care is necessary in handling the anhydrous salt, to prevent its hydration.
Chemical Properties
White, crystalline, deliquescent powder;
sharp saline taste.Soluble in water and hydrogen
fluoride, insoluble in alcohol.
Chemical Properties
Potassium fluoride is a white crystalline
solid.
Uses
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Industry
Application
Role/benefit
Organic synthesis
Preparation of various organic fluoride
Fluorinating agent/replaces other halide ions like chlorine, bromine etc.
Chemical manufacture
Manufacture of polyurethanes and alkyl benzenes
Catalyst/promote the reaction rate
Manufacture of pesticides and insecticides
Fluorinating agent; ingredient
Manufacture of potassium bifluoride
Raw material
Metallurgy
Soldering
Soldering fluxes/help to remove oxide film
Tin plating
Plating composition/source of fluoride
Glass
Etching of glass
Glass etching composition; source of fluoride
Others
Food and wood preservative
Source of fluoride
Absorption of hf and moisture
Adsorbent/anhydrous potassium fluoride has hydroscopicity
Complexometric titration of tantalum
Masking agent
Extraction of tantalum from ore
Precipitator/reacts with fluorotantalic acid to precipitate potassium fluorotantalate
Uses
Potassium fluoride is used in metal finishing, batteries, coatings and photographic chemicals. It is utilized for the study of ion-specific swelling and de-swelling of ampholytic polymer gels as well as in the measurement of electronic polarizabilities of ions in polymers of alkali halides. It finds application in the electronic industry as a metal surface treatment product. It is used as a preservative, a food additive, a catalyzer and a water absorbing agent. In the Finkelstein reaction, it is actively involved in the conversion of chlorocarbons to fluorocarbons using polar solvents like dimethyl formamide and ethylene glycol.
Definition
ChEBI: Potassium fluoride is a fluoride salt having K+ as the counterion. It has a role as a poison. It is a fluoride salt and a potassium salt.
Reactivity Profile
Potassium fluoride reacts with acids to evolve corrosive and toxic hydrogen fluoride. Aqueous solutions corrode glass and consequently are prepared and stored in polyethylene containers. The pure solid may be stored in glass containers. Reacts violently with (Pt + BrF3). [NTP 1992].
Hazard
Toxic by ingestion and inhalation, strong
irritant to tissue.
Health Hazard
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Fire Hazard
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
Safety Profile
Poison by ingestion and
intraperitoneal routes. Moderately toxic by
subcutaneous route. Experimental
teratogenic effects. A corrosive irritant to
the eyes, skin, and mucous membranes.
Mutation data reported. A very reactive
material. When heated to decomposition it
emits toxic fumes of K2O and F-. Used in
etchmg glass, as a presewative, as an
insecticide, and in organic synthesis. See also
FLUORIDES and HYDROFLUORIC
ACID.
Potential Exposure
Potassium fluoride is used in etching
glass; as a preservative and insecticide.
Incompatible with strong acids; reacts
releasing hydrogen fluoride. Aqueous solutions corrode
glass and consequently are prepared and stored in polyeth-
ylene containers. The pure solid may be stored in glass
containers. Reacts violently with (Pt 1 BrF 3 )
Potassium fluoride Preparation Products And Raw materials
