potassium fluoride potassium fluoride potassium fluoride is the chemical compound with the formula kf. after hydrogen fluoride, kf is the primary source of the fluoride ion for applications in manufacturing and in chemistry. it is an alkali halide salt and occurs naturally as the rare mineral carobbiite. solutions of kf will etch glass due to the formation of soluble fluorosilicates, although hf is more effective. potassium fluoride names iupac name potassium fluoride identifiers cas number 7789-23-3 (anhydrous) y13455-21-5 (dihydrate) y 3d model (jsmol) interactive image chembl chembl1644027 n chemspider 23006 y echa infocard 100.029.228 ec number 232-151-5 pubchem cid 522689 rtecs number tt0700000 unii 9082wg1g3f y95r1d12heh (dihydrate) y comptox dashboard (epa) dtxsid8031940 inchi inchi=1s/fh.k/h1h;/q;+1/p-1 ykey: nrokbhxjspedar-uhfffaoysa-m yinchi=1s/fh.k/h1h;/q;+1/p-1key: nrokbhxjspedar-rewhxwofaikey: nrokbhxjspedar-uhfffaoysa-m smiles . properties chemical formula kf molar mass 58.0967 g/mol (anhydrous) 94.1273 g/mol (dihydrate) appearance colourless density 2.48 g/cm3 melting point 858 °c (1,576 °f; 1,131 k) (anhydrous) 41 °c (dihydrate) 19.3 °c (trihydrate) boiling point 1,502 °c (2,736 °f; 1,775 k) solubility in water anhydrous: 92 g/100 ml (18 °c) 102 g/100 ml (25 °c) dihydrate: 349.3 g/100 ml (18 °c) solubility soluble in hf insoluble in alcohol magnetic susceptibility (χ) −23.6·10−6 cm3/mol structure crystal structure cubic hazards ghs labelling: pictograms signal word danger hazard statements h301, h311, h331 precautionary statements p261, p264, p270, p271, p280, p301+p310, p302+p352, p304+p340, p311, p312, p321, p322, p330, p361, p363, p403+p233, p405, p501 nfpa 704 (fire diamond) 3 0 0 flash point non-flammable lethal dose or concentration (ld, lc): ld50 (median dose) 245 mg/kg (oral, rat) related compounds other anions potassium chloridepotassium bromidepotassium iodide other cations lithium fluoridesodium fluoriderubidium fluoridecaesium fluoridefrancium fluoride except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references preparation potassium fluoride is prepared by reacting potassium carbonate with hydrofluoric acid. evaporation of the solution forms crystals of potassium bifluoride. the bifluoride on heating yields potassium fluoride: k 2 co 3 + 4 hf ⟶ 2 khf 2 + co 2 ↑ + h 2 o khf 2 ⟶ kf + hf ↑ platinum or heat resistant plastic containers are often used for these operations. potassium chloride converts to kf upon treatment with hydrogen fluoride. in this way, potassium fluoride is recyclable. crystalline properties kf crystallizes in the cubic nacl crystal structure. the lattice parameter at room temperature is 0.266 nm. applications in organic chemistry in organic chemistry, kf can be used for the conversion of chlorocarbons into fluorocarbons, via the finkelstein (alkyl halides) and halex reactions (aryl chlorides). such reactions usually employ polar solvents such as dimethyl formamide, ethylene glycol, and dimethyl sulfoxide. more efficient fluorination of aliphatic halides can be achieved with a combination of crown ether and bulky diols in acetonitrile solvent. safety considerations like other sources of the fluoride ion, f−, kf is poisonous, although lethal doses approach gram levels for humans. it is harmful by inhalation and ingestion. it is highly corrosive, and skin contact may cause severe burns.