It consists of a double fluoride of aluminum, and only requires to be mixed with an excess of sodium and heated, when the mineral aluminum at once separates.
The hydrogen gas, combining with the fluoride, "forms hydrofluoric acid, which is taken up by the iron and is thereby converted into fluoride of iron.
The fluoride of aluminum is placed in shallow trays or dishes, each dish being surrounded by clean iron filings placed in suitable receptacles; dry hydrogen gas is forced in, and suitable entry and exit pipes and stop-cocks are provided.
Powdered fluoride of aluminum is placed alone or in combination with other fluorides in a closed furnace, heated to a red heat, and exposed to the action of hydrogen gas, which is used as a reagent in the place of sodium.
Berzelius, by converting silverfluoride into silver chloride, obtained the value 19.
Sulphurous acid and sulphites are chiefly used in the preservation of thin ales, wine and fruit, and sodium fluoride has been found in butter.
Defn: A fluoride of the cerium metals occurring in hexagonal crystals of a pale yellow color.
It occurs naturally, principally combined as calciumfluoride in fluorite, and as a double fluoride of aluminium and sodium in cryolite.
Defn: Pertaining to, or denoting, a compound consisting of a double fluoride of hydrogen and silicon; silicofluoric.
Defn: A fluoride of alumina and soda occurring with the Greenland cryolite in octahedral crystals.
Defn: A fluoride of cerium, occuring near Fahlun in Sweden.
It is a hydrous fluoride of cerium, yttrium, and calcium.
Defn: A double fluoride of zirconium and hydrogen, or some other positive element or radical; as, zircofluoride of sodium.
It is produced by the action of silicon fluoride on water, and is regarded as an acid, H2SiF6, and the type and origin of the silicofluorides.
Defn: A fluorideof aluminium, calcium, and sodium occurring with the cryolite of Greenland.
For dyeing with the Alizarine colours, using chrome fluorideas the mordant, it can be applied with fair success.
With fluoride of chrome either oxalic acid or tartar is used, and a deposit of chromium oxide is formed on the wool, the general effect being the same as when bichromate of potash is used with oxalic acid or tartar.
As mordanting materials bichromate of potash and fluoride of chrome are chiefly used when chrome mordants are required, sometimes chrome alum.
Fluoride of chrome, chrome acetate, or alum, may be used as mordants if necessary.
Boron fluoride (BF{3}) is very similar to silicon fluoride in its mode of formation and chemical properties.
This liquid is not an electrolyte, but becomes such when potassium fluoride is dissolved in it.
Of these siliconfluoride is the most familiar and interesting.
Phosphorite and sombrerite are mineral forms of calcium phosphate, while apatite consists of calcium phosphate together with calcium fluoride or chloride.
The forces which here come into play appear to be considerably greater than those just mentioned; for instance, potassium fluoride is perhaps the most stable of all known compounds.
In the formation of healthy bones and teeth, calcium fluoride is essential.
I have composed this cell-food, containing the necessary fluoride of lime, in this particular way in order to avoid too much specialization.
It appears in this form in the cartilaginous matter of the eye lenses, and lack of calcium fluoride in the food results in the clouding of these lenses.
From the doublefluoride of potassium and hydrogen.
Phosphate of calcium, with a little fluoride of calcium 53.
A simple modification of the process is to wet the design with sulphuric acid, and then to sprinkle on some finely pulverised fluor spar (fluoride of calcium), by which means hydrofluoric acid is set free and attacks the glass.
This acid liquor, which is a double fluoride of silicon and hydrogen, is used as a test for barium and potassium, with which it forms nearly insoluble precipitates.
A native double fluoride of aluminium and sodium, found in large quantities in Greenland, employed in the manufacture of alum, and also as a source of metallic aluminium.
It also occurs as phosphate in monazite, and as fluoride in fluocerite.
Silica and potassium silico-fluoride are precipitated, and hydrochloric acid is set free.
Consequently, it is incorrect to speak of such compounds as chloride of potash, fluoride of lime, &c.
Silica is detected by heating the substance with a fluoride and sulphuric acid in a platinum-crucible.
It attacks silica, forming fluoride of silicon, which is a gas.
Penfield uses a similar arrangement, but passes his silicon fluorideinto an alcoholic solution of potassium chloride.
Silicon fluoride is evolved, and, if a moistened glass rod is held in the tube, it becomes coated with a white deposit of silica, formed by the decomposition of the silicon fluoride by the water.
Fluorine is frequently met with as calcium fluorideor fluor-spar (CaF{2}).
This liquid fluorideof iodine attacks glass with great energy and decomposes water when dropped into that liquid with a noise like that produced by red-hot iron.
Calcium phosphate is attacked in the cold like lime, giving out a brilliant white light, and producing calcium fluoride and gaseous oxyfluoride of phosphorus, POF{3}.
Gold becomes converted into a yellow deliquescent volatile fluoride when heated to low redness, and at a slightly higher temperature thefluoride is dissociated into metallic gold and fluorine gas.
To remove the last traces of hydrofluoric acid, advantage is taken of the fact that fused sodium fluoride combines with the free acid with great energy to form the double fluoride HF.
Thallium is rapidly converted tofluoride at ordinary temperatures, the temperature rising until the metal melts and finally becomes red hot.
A gaseous fluoride of sulphur is formed, which possesses a most penetrating odor, somewhat resembling that of chloride of sulphur.
Sodium fluoride also possesses the advantage of not attracting moisture.
With a small quantity of water a brownish yellow solution is formed, which, however, in a very short time becomes warm and the fluoride decomposes; platinic hydrate is precipitated, and free hydrofluoric acid remains in solution.
Its properties agree with those of the fluoride of iodine prepared by Gore by the action of iodine on silver fluoride.
This is the case where much calcium carbonate or fluoride is present in the raw phosphate, as both of these compounds require a quantity of acid for their decomposition, which takes place before the decomposition of the phosphate.
It most abundantly occurs as apatite, a mineral consisting of calcium phosphate, with small quantities of calcium fluoride or calcium chloride.
The first consists of calcium phosphate along with calcium fluoride; and in other kinds of apatite the calcium fluoride is replaced by calcium chloride.
A fluoride of cerium, occuring near Fahlun in Sweden.
Pertaining to, or denoting, a compound consisting of a doublefluoride of hydrogen and silicon; silicofluoric.
Cryolite is not a safe body to electrolyse, because the minimum voltage needed to break up the aluminium fluoride is 4.
As a part of the voltage is consumed in the latter duty, only the residue can be converted into chemical work, and as the theoretical voltage of the aluminiumfluoride in the cryolite is 4.
NaF) is a double fluoride of aluminium and sodium, which is scarcely known except on the west coast of Greenland.
Of the simple compounds, only the fluoride is amenable to electrolysis in the fused state, since the chloride begins to volatilize below its melting-point, and the latter is only 5 deg.
Grabau patented a method of reducing the simple fluoride of aluminium with sodium, and his process was operated at Trotha in Germany.
It has been found, however, that molten cryolite and the analogous double fluoride represented by the formula Al2F6.
Sainte-Claire Deville formed the zircon artificially by passing silicon fluoride at a red heat over the oxide zirconia in a porcelain tube.
Verneuil obtained artificial rubies by reacting at a red heat with barium fluoride on amorphous alumina containing a small quantity of chromium.
Boron fluoride also combines with ammonia gas, equal volumes of the two gases giving a white crystalline solid of composition BF3.
But the action of fluorine on metals at the ordinary temperature is comparatively feeble, because the metallic fluoride formed coats the remaining mass of the metals; it is, however, completely absorbed by iron.
Thus the silver compounds of the latter are insoluble in water, whilst silver fluoride is soluble.
If a deep marking is desired, in order that it may afterwards be filled with some pigment, a better result is obtained by the use of liquid commercial hydrofluoric acid, which is a solution of hydrogen fluoride in water.
A little of the commercial hydrofluoric acid, or a mixture of a fluoride and sulphuric acid, is distributed over the bottom of the trough, and the whole arrangement is allowed to stand for about an hour.
Since thefluoride ion is colorless, the color of the soil depends upon the predominant metal in the region.
To have done so would have been instant death; the air was a mixture of free fluorine and fluoride gasses, the soil was metallic fluorides, damp with acid rains, and the river was pure hydrofluoric acid.
Fluorspar or calcium fluoride is the most important salt of hydrofluoric acid.
It is also convenient to prepare the hydrofluoric acid extemporaneously by the action of sulphuric acid on fluoride of sodium; and, in many cases, it is advisable to thicken up the film by an additional layer of gelatine.
A volume of the dilute sulphuric acid equal to about one-fourth of the fluoride solution is next added from the first dish, and the plate is then transferred to the second dish, when the film soon becomes liberated.
Silicic fluoride is a colourless gas, with a very pungent odour, fuming strongly in the air, and neither burning nor supporting combustion.
The potassic fluoride is got rid of by washing with cold water, its entire removal being indicated by the water ceasing to have an alkaline reaction on test paper, whilst amorphous silicon is left behind in the form of a brown powder.
It is now procured much more easily by the decomposition of silico-fluoride of potassium, at an elevated temperature, with potassium or sodium.
By heating a mixture of fluorspar and ground flints with sulphuric acid a gaseous tetra-fluoride of silicon is formed, which, being partially soluble in water, yields an acid solution of the tetra-fluoride.
With twice its volume of ammoniacal gas silicicfluoride combines to form a crystalline volatile.
Another method of manufacture of commercial soda is by treating the mineral cryolite (a double fluoride of sodium and aluminium) with either caustic, or hydrate of lime.
It may be obtained in a state of absolute purity by passing gaseous fluoride of silicon into water, collecting the resulting gelatinous precipitate on a calico filter, washing it with distilled water, drying it, and heating it to redness.
The philosophy of the action is the decomposition of the ammonium fluoride by the acid, which attacks the glass; the barium sulphate is inert, and is simply used to prevent the spreading of the markings.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "fluoride" in a variety of sentences. We hope that you will now be able to make sentences using this word.
