Potassium Fluoborate

Salts of fluoboric acid are nearly always contaminated by fluorides. The reason for such contamination is twofold. In the first place, the reaction by means of which fluoboric acid is formed is reversible, and, in the second place, most of the common salts of fluoboric acid crystallize as hydrates which show a marked tendency to hydrolyze with their water of hydration. Drying at higher temperatures markedly increases the rate of hydrolysis. 

Potassium fluoborate possesses certain distinct advantages over the other salts of fluoboric acid. Not only can 

The calculated quantity of concentrated (47 per cent) hydrofluoric acid is placed in a platinum dish set in an ice bath. The required amount of solid boric acid is then added in very small portions at intervals of several minutes. f After all of the boric acid has been added, the solution is allowed to stand at room temperature for five or six hours to allow the reaction to proceed with the formation of a maximum quantity of fluoboric acid. 

The dish containing the solution of fluoboric acid is again placed in an ice bath, and 5N potassium hydroxide solution is added slowly, with stirring, until a test portion gives an alkaline reaction with methyl orange. The solution is kept in an ice bath until it is chilled and the crystals of potassium fluoborate have settled. 

The crystal mass is then separated from the mother liquor by careful decantation or by filtration through a Buchner funnel. In either case, the product is carefully washed several times with cold distilled water, f then with 95 per cent ethyl alcohol and with ether. If the crystals are washed by decantation, the yield may not exceed 75 per cent. If absolute purity is not essential, and filtration is carried out on the Buchner funnel, the yield may be considerably higher as indicated by the following experimental results. 

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Kaiium, n. potassium, -alatm, m. potassium alum, -azetat, n. potassium acetate, -bor-fluorid, n. potassium fluoborate. -brech-weinstein, m. antimonyl potassium tartrate, tartar emetic. 

Modification of the burning rates, pressure exponents, and temp coefficients of burning rate of the fluorocarbon composites has been accomplished with copper, lead, tin, sodium, ammonium and potassium fluoborates sodium, potassium, lithium, lead, copper and calcium fluorides potassium and ammonium dichromate lead and zinc stearate cesium carbonate potassium and ammonium sulfate copper chromite oxides of magnesium, copper and manganese boron zinc dust and carbon black (Ref 75)... 

Potassium Borofiuoride, poto ssium Fiuoro-borate or Potassium Fluoborate, KBF4, mw... 

To prepare boron trifluoride, mix 50 g of potassium fluoborate and 9 g of boric acid anhydride in flask 3, and pour 25 ml of anhydrous sulphuric acid into the mixture. Prepare the anhydrous sulphuric acid by adding the relevant amount of 65 % oleum to a 96 % sulphuric acid solution carefully, wear eye protection ). 

The potassium fluoborate prepared in the foregoing manner is stable for an indefinite period in the dry state. Fresh solutions of the compound give no precipitate of lead fluochloride when added to a filtered, saturated solution of lead chloride. Such solutions are stable for several hours after preparation, but hydrolysis takes place gradually. Samples of pure potassium fluoborate prepared using every precaution indicated in the foregoing procedure were found to have the following composition ... 

Plumbous thiocyanate, 85 Potassium, metallic, 79 Potassium azide, 79 Potassium chlororhenite, 178 Potassium fluoborate, 24 Potassium iodide, use as a primary standard, 163... 

Note See Potassium Fluoborate about color phenomena appearing in coned solns of fluoboric acid. 

Borate(l-), tetrafluoro-, potassium. See Potassium fluoborate Borate(l-), tetrafluoro-, tin (2+) (2 1). See Stannous fluoroborate Borate (1-), tetrahydro-, potassium. See Potassium borohydride Borax Borax, Borax decahydrate. See Sodium borate decahydrate Borax, fused. See Sodium borate Bordeaux RRN. See Pigment orange 43 Bordeaux F2R. See Pigment red 12... 

Potassium ferrocyanide. See Potassium ferricyanide Potassium fluoborate... 

Tetrafluoroborate (1-) potassium. See Potassium fluoborate Tetrafluoroboric acid. See Fluoboric acid Tetrafluorodichloroethane 1,1,2,2-Tetrafluoro-1,2-dichloroethane. See 1,2-Dichlorotetrafluoroethane Tetrafluorodichloromethane. See Dichlorotetrafluoromethane Tetrafluoroethane... 

Boric acid Molybdenum pentachloride Potassium fluoborate Trimethyl borate brazing flux, gaseous Tri methyl borate bread improver mfg. 

Aluminum calcium silicate filler, reactive flame retardant paper Tetrabromophthalic anhydride filler, reactive flame retardant textiles Tetrabromophthalic anhydride filler, reactive flame retardant unsat. polyesters Tetrabromophthalic anhydride filler, reactive resin-based grinding wheels Potassium fluoborate filler, refractories... 

Hydrobromic acid Levulinic acid Methyl acid phosphate Potassium fluoborate Sodium borate... 

Dihydroxyethyl stearamine oxide 14073-97-3 l-Menthone 14075-53-7 Potassium fluoborate 14097-03-1 Basic red 18 14103-61-8 Diisononyl phthalate Diplast N 14117-96-5 Distearyl phthalate 14150-71-1... 

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