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Hydrogen fluoride aqueous

Aqueous hydrogen fluoride is a weak acid (see above) and dissolves silica and silicates to form hexafluorosilicic acid hence glass is etched by the acid, which must be kept in polythene bottles. [Pg.330]

Anhydrous hydrogen fluoride is also available in cylinders, and aqueous hydrogen fluoride, either 50% or 70%, is also shipped in polyethylene bottles and carboys. Typical product specifications and analysis methods are given in Table 4. [Pg.197]

Aqueous hydrogen fluoride of greater than 60% maybe handled in steel up to 38°C, provided velocities are kept low (<0.3 m/s) and iron pickup in the process stream is acceptable. Otherwise, mbber or polytetrafluoroethylene (PTFE) linings are used. For all appHcations, PTFE or PTEE-lined materials are suitable up to the maximum use temperature of 200°C. PTEE is also the material of choice for gasketing. AHoy 20 or Monel is typically used for valve and pump appHcations. Materials unacceptable for use in HE include cast iron, type 400 stainless steel, hardened steels, titanium, glass, and siHcate ceramics. [Pg.198]

The discovery of the Balz-Schiemann reaction in 1927 replaced the earlier Wallach procedure (1886) based on fluorodediazoniation of arenediazonium piper-idides (aryltriazenes) in aqueous hydrogen fluoride [40 41]... [Pg.277]

Nobel Prize for chemistry 1906). Produced by electrolysis of potassium fluoride in aqueous hydrogen fluoride (HF). [Pg.36]

Diisopropylamine trihydrofluoride (1). The salt is obtained by addition of 3 equiv. of aqueous hydrogen fluoride to the amine. [Pg.141]

A determination of the heats of solution of germanium dioxide and tetrafluoride in aqueous hydrogen fluoride, to give the same final composition of fluorogermanic acid, when taken in conjunction with the precisely known heats of formation of the solids should also yield a precise value of Aif((HF(aq)) from the overall reaction heat of... [Pg.17]

The polymerization products of propylene have been observed to be saturated hydrocarbon polymers and terpenelike unsaturated hydrocarbons (Kuhn, 64). The condensation of formaldehyde with phenols and cyclohexanols by means of aqueous hydrogen fluoride has also been observed (Badertscher el al., 65). [Pg.219]

The largest tonnage product, fluorobcnzcnc (3), is manufactured by the diazotization of aniline (1) in strong aqueous hydrogen fluoride. The intermediate diazonium fluoride 2 is decomposed in situ without isolation from solution. Despite the considerable safety and corrosion problems presented by the reaction mixtures, the technology was developed in the 1980s to provide a worldwide capacity of several thousand tons. Other fluoroaromatics such as fluorotoluenes are also manufactured by this route. [Pg.75]

Silver(I) fluoride can be obtained by reaction of silver(I) oxide with 40 % aqueous hydrogen fluoride.30... [Pg.645]

Androst-4-ene-3,ll,17-trione, 88, 377, 409 di-Androst-5-en-3/3-oI, 199 Androst-5-en-17-ol-3-one, 32 Androst-l-en-3-one, 152 Androst-4-en-3 -one, 152 5a-Androst-8-en-l 1-one, 189 5 -Androst-8(14)-en-15-0ne, 155 Anhydrous hydrogen fluoride, 425 Aqueous hydrogen fluoride, 435 Argentic picolinate, 241 17a-aza-D-homo-estrone methyl ether, 163... [Pg.259]

Another method of preparation described is the treatment of activated aluminum oxide with 1 % aqueous hydrogen fluoride (HF/A1,0, molar ratio = 0.26) in a polyethylene vessel.15 The aluminum trifluoride is filtered oil and dried for 6 hours at 120 C. A catalyst produced in this manner reduces the evolution of hydrogen chloride during the subsequent disproportionation reaction. [Pg.281]


See other pages where Hydrogen fluoride aqueous is mentioned: [Pg.138]    [Pg.178]    [Pg.193]    [Pg.225]    [Pg.262]    [Pg.468]    [Pg.425]    [Pg.435]    [Pg.496]    [Pg.248]    [Pg.217]    [Pg.173]    [Pg.219]    [Pg.3]    [Pg.468]    [Pg.1]    [Pg.96]    [Pg.98]    [Pg.98]    [Pg.130]    [Pg.239]    [Pg.689]    [Pg.689]    [Pg.707]    [Pg.712]    [Pg.726]    [Pg.257]    [Pg.482]    [Pg.487]    [Pg.131]    [Pg.131]    [Pg.140]    [Pg.24]    [Pg.240]   
See also in sourсe #XX -- [ Pg.435 ]

See also in sourсe #XX -- [ Pg.168 ]




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