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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 ...
Oxygen difluoride was first reported in 1929; it was obtained by the electrolysis of molten potassium fluoride and hydrofluoric acid containing small quantities of water. [7] [8] The modern preparation entails the reaction of fluorine with a dilute aqueous solution of sodium hydroxide, with sodium fluoride as a side-product:
Lead(II) fluoride can be prepared by treating lead(II) hydroxide or lead(II) carbonate with hydrofluoric acid: [3]. Pb(OH) 2 + 2 HF → PbF 2 + 2 H 2 O Alternatively, it is precipitated by adding hydrofluoric acid to a lead(II) salt solution, or by adding a fluoride salt to a lead salt, such as potassium fluoride to a lead(II) nitrate solution, [4]
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 ...
Potassium fluoroborate is obtained by treating potassium carbonate with boric acid and hydrofluoric acid. B(OH) 3 + 4 HF → HBF 4 + 3 H 2 O 2 HBF 4 + K 2 CO 3 → 2 KBF 4 + H 2 CO 3. Fluoroborates of alkali metals and ammonium ions crystallize as water-soluble hydrates with the exception of potassium, rubidium, and cesium.
Silicon wafers are treated with solutions of electronic-grade hydrofluoric acid in water, buffered water, or alcohol. One of the relevant reactions is simply removal of silicon oxides: SiO 2 + 4 HF → SiF 4 + 2 H 2 O. The key reaction however is the formation of the hydrosilane functional group.
Germanium tetrafluoride is a noncombustible, strongly fuming gas with a garlic-like odor. It reacts with water to form hydrofluoric acid and germanium dioxide. Decomposition occurs above 1000 °C. [5] Reaction of GeF 4 with fluoride sources produces GeF 5 − anions with octahedral coordination around Ge atom due to polymerization. [6]