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It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid. It is the principal industrial source of fluorine, often in the form of hydrofluoric acid, and is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers such as polytetrafluoroethylene (PTFE).
SiO 2 + 6 HF → H 2 SiF 6 + 2 H 2 O. A 5% to 9% hydrofluoric acid gel is also commonly used to etch all ceramic dental restorations to improve bonding. [6] For similar reasons, dilute hydrofluoric acid is a component of household rust stain remover, in car washes in "wheel cleaner" compounds, in ceramic and fabric rust inhibitors, and in water ...
The optional second step (for bare silicon wafers) is a short immersion in a 1:100 or 1:50 solution of aqueous HF (hydrofluoric acid) at 25 °C for about fifteen seconds, in order to remove the thin oxide layer and some fraction of ionic contaminants. If this step is performed without ultra high purity materials and ultra clean containers, it ...
Elemental fluorine and virtually all fluorine compounds are produced from hydrogen fluoride or its aqueous solution, hydrofluoric acid. Hydrogen fluoride is produced in kilns by the endothermic reaction of fluorite (CaF 2) with sulfuric acid: [169] CaF 2 + H 2 SO 4 → 2 HF(g) + CaSO 4. The gaseous HF can then be absorbed in water or liquefied ...
SiO 2 + 4HF + 2NH 4 F → (NH 4) 2 SiF 6 + 2H 2 O. Concentrated HF (typically 49% HF in water) etches silicon dioxide too quickly for good process control and also peels photoresist used in photolithographic patterning. Buffered oxide etch is commonly used for more controllable etching. [1] Buffering HF with NH 4 F results in a solution with a ...
Lutetium(III) fluoride can be produced by reacting lutetium oxide with hydrogen fluoride, or reacting lutetium chloride and hydrofluoric acid. [8] It can also be produced by reacting lutetium sulfide and hydrofluoric acid: [9] 3 Lu 2 S 3 + 20 HF + (2 + 2x) H 2 O → 2 (H 3 O)Lu 3 F 10 ·xH 2 O↓ + 9 H 2 S↑ (x = 0.9) (H 3 O)Lu 3 F 10 → 3 ...
OF 2 reacts with many metals to yield oxides and fluorides. Nonmetals also react: phosphorus reacts with OF 2 to form PF 5 and POF 3; sulfur gives SO 2 and SF 4; and unusually for a noble gas, xenon reacts (at elevated temperatures) yielding XeF 4 and xenon oxyfluorides. Oxygen difluoride reacts with water to form hydrofluoric acid: OF 2 + H 2 ...
This neutralization reaction forms hydrogen fluoride (HF), the conjugate acid of fluoride. In aqueous solution, fluoride has a p K b value of 10.8. It is therefore a weak base , and tends to remain as the fluoride ion rather than generating a substantial amount of hydrogen fluoride.